If you’re not having progress with your Aneros, so long as it isn’t hurting, do keep giving it a go from time to time. There’s a comment in the sidebar that “some guys have spent years getting there”; take that literally.
I suspect I got my Aneros back in 2005, give or take a year. I bought it at the point believing there was only one model and was surprised to receive one called a MGX – this might help people be able to place it in time. It probably took me several years and a lot of effort and exaggerated clenching to get any sort of reaction, and for the longest time I would try the “lots of deep breathing, fifteen full clenches then hold it quarter-way” routine. I might get one pleasant sensation, though not always, then that would be it in terms of anything pleasurable for the session. I would keep trying and trying and get nothing further. There were two occasions, years apart, where I clenched so much that for several (5? 7?) days afterwards I felt like I had bruised myself internally and felt like I was buzzing inside, in a not-at-all pleasant way, to the point where sitting down was uncomfortable. Ever since then I’ve taken it more easily.