My favorite CBT scene involves self-inflicted abrasion. After the Domme ties me up, she mixes up some hand lotion with some sand, little pieces of rock salt, salt, and tabasco sauce. Then she teases me for several hours until I'm desperate for an orgasm. She coats my cock with the 'lube' and coats my right hand with it. Next she unlocks my right hand and sits back to watch the fun. I try to resist but I can't and I masturbate with the gritty 'lube', scratching the hell out of my cock. When I finish, she re-locks my right hand and watches me squirm for a while as the salt and tabasco find their way into all the little scratches on my cock from the gritty masturbation 'lube.'

Another favorite is to simply have my cock wrapped in steel wool for a while. You can buy steel wool pads with holes in the center that fit nicely around a cock. Then I get dressed and I'm off for a day of errands, a visit to the mall, etc. After a few hours the pain is intense and the damage lasts for several days.