Today I received my Peridise Anal PC Toy lubed up and started with the smaller of the two. The directions say not to force it in – to just put it in let your own body position where it wanted to be. Then it says to contract your sphincter muscles several times to advance the Peridise in to the anal canal. I lay there for a bit getting accustomed to how it felt and played around with different contracting and relaxing exercises for a bit. While doing this I started to feel my sphincter and anus build up some energy during those contractions. I started relaxing, and pretty soon my anus started winking and fluttering on it's own, with each contraction building on top of the other one (before the previous contraction had a chance to release or contract) and they started stacking up on top of each other. I had a very strong mini-o similar to ones I have felt with the Aneros Helix massager and the Peridise went in and out of my anus with each involuntary contraction, rubbing aginst my prostate. It did not seem to be massaging my prostate in the exact same way as the Helix, but I could definitely feel it rubbing there pleasurably, and it definitely caused my sphincter to go on a wild ride for a bit. Unfortunately I was not able to continue my session for as long as I would like to have, and did not get a chance to check out the larger of the 2 yet, but I will definitely use the Peridise as a prelude to my future sessions with a prostate mass