I've never done anything involving mind control or hypnotism in ERP, but I -did- have an ERP partner that would Skype call me and hypnotise me OOC. I'm not sure exactly how well it worked.. I distinctly remember wanting to do the things he told me to do, not so much that I was directly controlled by him. There was this one feeling I would get though as he was guiding me into a trance that I suddenly began to feel very heavy and weighty, as though all my limbs were too heavy to move and that all I could do was lie there and breathe, powerless to stop whatever might happen to me, and that was insanely hot. He had me take a tray of ice cubes and alternate them between my mouth and vagina until they melted, piece by piece, making me suck on them or squeeze my thighs together or hold them against my clit or nipples. I forget exactly how things played out next but I just remember feeling warm, safe, comfortable, telling me what a good little slut I was and how well I was doing.. and I can't even remember how it happened but holy -crap- I had one of the best orgasms in my life. I came so hard when he pushed me over the edge, the inside of my body had stopped cumming but my hips kept spasming and I couldnt talk, and I was afraid my neighbor would hear me through the door so I had to bury my face into the arm of the couch to muffle myself because god, I couldnt stop shaking. Usually the first time I orgasm it's pretty forgettable and I dont really "climax" until the second time, but I came so hard that after I finally stopped shaking I was filled with this instant sense of gratification, this full feeling and warmth, this like, perfect contentment with no desire to continue, just wanting to lay there and feel how warm and soft and good I felt, and I remember being SUPER giggly. Everything made me giggle and I was in like the absolute best mood for the next day. It was AMAZING. Ugh.
unfortunately this story does not have a happy ending because I have INSANE anxiety / mental health issues and I became so embarrassed and ashamed of what I had done that I blocked him and never got the courage to speak to him again because I convinced myself that I was beneath him and I didnt deserve to bother him.
But yeah, that's my experience with it anyway. I'd like to try it in ERP sometime, I just dunno where to start.