While I have used the aneros a number of times on a bed to only moderate results, I have found that it works best for me when I am at the gym, in the sauna, believe it or not.
The sauna I go to isn't very crowded, in fact there are hours at a stretch where no one at all comes in or out, and one can be there quietly for a long time. I have my aneros in a pouch with a pot of lube and sit on the slatted bench for a while, working up a sweat. Eventually I take a couple fingers of lubricant and work it into my anus while sitting on my towel. then dipping the aneros in, get it covered with lube. Usually I lie on m y side to get it in the best way, and the final pop through the second sphincter really is a sweet thing. Then the anus closes over it, and you are set to go.
I find that actually sitting on the bare slats with the aneros handle fitting between them works great, and sitting with my back against the wall and knees up allows me to pulse the anal sphincter and get some fairly good results.
If anyone comes in, no problem; they are either gay and enjoy watching me, or else I am just sitting there and they don't know any difference.
Then I find the most pleasurable sensations happen when I stand up and bend forward with my legs spread out. wow - what a buzz that gives me.
Sometimes I pull on the curly handle too, but what's most important is that with your body bent like that the prostate is well disposed to expressing fluid, and when I'm warmed up and bent over the milky prostatic fluid just plops out of my dick with a thick dripping onto the floor.
If it gets too much I can sit down again, but it's very intense. The official instructions may not say to do such things, but the usual lying on my back in bed just doesn't make it as intense as standing, spreading, and bending.