Fisting allows me to let go. It is much more intense than an enema. I like to get fisted in front of people I know, so that there are witnesses who can confirm it really happened
It is a deep, hard experience, not quite as intimate as an enema, but you have to trust the other person. My husband and I got a teacher, and we have taught others. We don't quite have "parties" per se, just one or two couples who want to "go deeper" so to speak.
I have difficulty getting in anything bigger than a hand up to the wrist.