What is this thing doing to my body?

@CollectingSmiles, welcome to the forum and congrats, you just jumped up the scale of re-wiring. You are discovering your chakras and strengthening the vibes between them. And the vocalization is very helpful as it is the response every of your chakras gives you on its specific level. Low chakra - low voice, high chakra - high voice. Mr Base is your gland. And this gland just has been awakened by this magic little piece of plastic! And as you already have learned this little piece of plastic activates a memory in the gland. Therefore you are able to revoke the sensation even without any Aneros tool inserted, called "Aless" around here.
I've been into four hours of Aless this morning without any ejaculation as for 28 days now, but with tremendous superOs and uncountable multiple orgasms. Your next step could be to try to separate your feelings and learn that your orgasm is not bound to your ejaculation, paving your path to become what Mantak Chia wrote about as a multiorgasmic man. If you want to understand your childish giggling as a great gift, I recommend to read this book, too.
You have already taken big steps on your journey, others don't reach in years, you're a lucky guy, don't forget to take a rest and enjoy Aless:
BTW, to begin your own blog in the blogs section helps to keep in memory the milestones of your journey. It looks like yours will go as fast as mine and sometimes it becomes hard to remember all those wonderful new experiences. If you don't want to lose yourself in the turbulence of your journey it might be a good idea to write down all your experiences.
Best vibes! And keep us posted!

I can relate to you. I've gone through somewhat the same experience, but not sure its good. I recently purchased one of these devices (peridise), and after using it a couple times, didn't really have much to say about it. Prior to getting one, I had been practicing kegels and was able to get the quivering muscles going with them, feel a good amount of arousal, but nothing too great.

But then after doing a couple more sessions I found myself thinking about nothing else but the next session, as I had the residual feelings down there. After about the 4th one I relieved myself with it still plugged in the old fashion way as I couldn't take it anymore, and really EXPLODED like never before. I thought this was great and looked forward to another session after a few days break.

Then after reading some posts about how to get more out of it, found that theres actually 3 muscle groups to try and engage. Previously i was using just the anus muscle (pulling in on the backside) and the PC (holding back the pee) and would use light tensions to get the muscles quivering (is this what they call the involuntaries?), just like I had been doing on my own with the kegels. But the third one is apparently the rectum muscle group (forcing out the ass). When I tried these three together, I got super aroused after a short session. I again relieved myself with it plugged in and it was good.

This is where it got actually kind of scary. That night I could feel something numbing down there, and there was an almost constant drip of precum. I went to bed but couldn't get to sleep because of these feelings. Its like my ass was demanding more. Trying to get to sleep, I found I was super sensitive to the feelings down there, and could only lie on my back to minimize the feelings. But after about 2 hours of this, I was starting to drift into sleep and rolled onto my stomach. Suddenly in this close to sleep state, I was violently awoken by this immense feeling in my lower abdomen, like a huge wave of energy just rolled through there. I've never felt anything like that. I immediately flipped off my stomach. WHAT WAS THAT? I was super aroused again, so went and relieved it again, went to bed, but an hour later, had to relieve it again. The next day due to no sleep was quite tired, but on the way to work was getting hard-ons in the car, tingling, numbness down there, precum, etc. all day. relieved myself when i got home again, went to bed that night and again wasn't able to get to sleep. This is getting a bit much by now. Went like this for about 3 days, and now about a week later, just some minor tingling and numbing down there. At least the precum has somewhat stopped. Haven't touched peridise again during all this time.

This experience was beginning to make me think I was becoming a total slave to these feelings, the desire for more was intense. I'm not going to try this again for quite some time so that I know I'm "normal" again. Don't want to become addicted or anything, but could see that happening very easily. Also, there is a condition that some people get where they get constant orgasms (google PGAD), I wonder if this is where this is going? Is that whats known as the re-wired state? Not good. And the lack of attention to anything like work during the day, its like I had ADD or something, could think of nothing but using that device with all the feelings going on all day.

I'm much more calmed down now after a week, but even so, I'm sure I could easily get something going without the device simply with some kegels but I don't want to experience another week of this torture again. Been relieving myself on a daily basis to try and keep it calm down there. Anyone know if this is because maybe just new to this, or is this how it becomes? I don't want to become a slave to my ass for the rest of my life...

What I didn't expect was what came after: a pleasant tingle in my hindquarters. Not an orgasm, but very enjoyable. Similar to the faint feeling I sometimes get when using the Helix, but amplified tenfold. Just a deep, ticklish tingle that had me giggling like an idiot for a solid minute or two. After a bit, it dwindled in strength but did not go away. Even stranger, I actually felt more aroused than when I'd started!

This is a pretty good description of an awakening prostate.

And yet again, after the third orgasm was done, the lower half of my body was buzzing with this strange tingle. ...For the past few days, I've had echoes of that feeling, most often when in a sitting position. It's particularly noticeable while driving. I don't know what's going on down there, but I like it.

From the Aneros WIKI - Glossary

butt buzz is persistent, even insistent, energy in your anus, rectum, prostate, perineum, scrotum/testicles area, sometimes experienced spontaneously apart from an Aneros session. Faint to mild muscle spasms leading up to an orgasm may also occur.
&
Echo Effect™(Jack Johnston) or after effect Spontaneous body sensation(s) felt after an Aneros session, these may include chair orgasms, mini-o's, butt buzz or other minor sensations.

Echo effects and butt buzz are totally normal for men on their Aneros journey, these are normal aspects of the body 'rewiring' itself to this new pleasure paradigm.

Am I right in thinking there's no way the supplements alone could be responsible for what happened to my body that night? What on Earth is this magic little piece of plastic doing to me?

While the supplements may or may not be contributors to your situation, what you have described is very much in accord with the 'rewiring' effects described by hundreds of your fellow Aneros users.

This is where it got actually kind of scary. ... I went to bed but couldn't get to sleep because of these feelings.... I was violently awoken by this immense feeling in my lower abdomen, like a huge wave of energy just rolled through there. I've never felt anything like that. ...WHAT WAS THAT? ...This is getting a bit much by now. Went like this for about 3 days, and now about a week later, just some minor tingling and numbing down there....This experience was beginning to make me think I was becoming a total slave to these feelings, the desire for more was intense. I'm not going to try this again for quite some time so that I know I'm "normal" again. Don't want to become addicted or anything, but could see that happening very easily. Also, there is a condition that some people get where they get constant orgasms (google PGAD), I wonder if this is where this is going? Is that whats known as the re-wired state? Not good. And the lack of attention to anything like work during the day, its like I had ADD or something, could think of nothing but using that device with all the feelings going on all day. ... Anyone know if this is because maybe just new to this, or is this how it becomes? I don't want to become a slave to my ass for the rest of my life...

I'm glad to hear you've been able to calm down. I believe what you have described is a case of unprepared Kundalini awakening. This is NOT a typical reaction to Aneros use or rewiring behavior but it is not unheard of either, there have been several of your fellow Aneros members that have gone through this experience. Ceasing Aneros use until you can come to terms with this phenomena is probably a good course of action. Once you have resolved the underlying psychological conditions, a return to pleasurable Aneros use will be possible. You may be able to accomplish this through self-help study or assistance of a qualified Yoga teacher. Here are a few threads which might shed some light on the situation for you -> Kundalini Rising, Have I Awakened my Kundalini? & All you rewired folks, Please help me. (kind of urgent). Good Vibes to You !

@CollectingSmiles You have summed it up thus: "I don't know what's going on down there, but I like it." This echoes the collective feelings of almost all Aneros users. There is something about the awakened prostate that we as males cannot ignore. Why is that? It is just too powerful and pervasive. But can't we just ignore it? I don't think so. Your Aneros (and sexual) "journey" has begun and you can't stop it. Nature will not let us ignore our sexuality. It is a "rainbow" of pleasures as you have discovered. Lie back and enjoy it!