2 years in: Has anyone jumpstarted this by masturbating before "hand"?

That never work for me.
You can't focus erotic energy to the penis, then expect those energies to somehow take a detour to the prostate.

I don't think you need to masturbate to the verge of ejaculation beforehand, but I think traditional penile masturbation with plenty of attention to prostate sensations is a good thing, both by itself and as a warm up before inserting the Aneros. One effective method is as follows: after getting fairly worked up, squat down and gently press the spot on the perineum immediately in front of the anus with two fingers. Your fingers should be as close to your anus as possible without actually touching it. I find that reaching around from the side (i.e., like when wiping) feels better than through the legs. Gently move the underlying flesh of that spot in a circular motion (your fingers should stay put on the surface of the skin). You should be able to feel the root of your erection, which otherwise gets no love during conventional masturbation. Keep your anus relaxed and use your free hand to play with your penis. Where you go from there is up to you, but this method always gets my prostate juices flowing.

I've done it both ways and I find I have more success when I do some penile masturbation before starting my Aneros session. What I like to do is just start by looking at some pictures or movies, or sometimes just reading things, and masturbate until I'm nice and turned on, but not to where I'm almost at the point of no return. Then I put everything away and set up my bed with the Aneros, a towel, my lube, etc. This takes a few minutes and in that time I'm usually flaccid again, and not quite as turned on - but still in the zone of feeling sexual and excited about what's coming next.

My biggest difficulty so far actually has been self-discipline with respect to not masturbating my way out of Aneros sessions when I start to feel really good. If I'm hovering on the border, having nice sensations but not quite going over the line, it's very tempting to just manually do it myself. The last couple sessions I've had I have managed to resist and I've been rewarded with some great breakthroughs. I still finish with a Super T, however.