How to avoid free hands wet orgasm

Hi there, any suggestion or advise of how to avoid the free hands wet orgasm and move to the dry orgasm next level, I like very much the FHO, as a matter a fact this is great I never experiment something like this before in my life, I feel really great after that, more alive and energetic, but I still aspire to achieve one day the big O's, still trying and learning. Also, how many FHO are ok a week, or how often is reasonable and healthy? Buy the way I achieved my FHO mostly on my back, with some cushion padding and some rocking back and fort and side to side of my hips, no hand involved or touching my penis neither the aneros device, but sometimes I feel some kind of sore inside me due to the rocking of my hips and contractions, last week after my session of FHO I felt some kind of sore inside my canal and my prostate, also I feel my penis a little sore at the head but like I was having a lots of sex, even though I did not touched at all during my session, FHO was great but I just have one five days before, maybe I doing something wrong. I used plenty of lubricant. Any advice or comment will be appreciate. Thx.

-golman