I hosted a show on behalf of SLOSH once, and asked my close friends if they wanted to come along. They sort of knew about my kink beforehand, and they offered to come along to support me and to act as stooges, to get the evening going. They were keen to take part and although didn't get that gunged, really got into it and got pied! They have said if the show happens again, they will want to come along and take part. I also think they like seeing me humiliated anyway!
However, I wouldn't ask if I could gunge then outside of this event, though i am sure if I did, they may do so! Never had the courage to do that bit! lol
The downside of this openess, is that they now make sarcastic comments and randome jokes about gunge etc!
There have been many I want to get messy that haven't been into the idea, but most that I've talked to have.
Most of the time I structure it into a situation where a few buds came over and I oddly had plenty of whipped cream in the fridge. We'd usually play a multiplayer video game or poker or something so bets came into play.
Most of the guys in my pics on my profile are not WAMmers and not' really know it as a kink. They were offered money to wear a speedo and get messy. The science behind the speedo: it cleans off faster - which is technically true.
Of the guys I've messed with, most of them were one time things, but I have a few repeat offenders that have really gotten to enjoy it. Actually messing with one tonight.