We did this a few years ago, and loved it! However, I'm not sure it would be everyone's idea of a good time.
Assuming it's still along the same lines as when we did it, I'd say that you have to be able to laugh at yourself, not worry about what anyone thinks about you or what you look like, and be prepared to go along with whatever is thrown at you!
If you want any detailed info, feel free to PM me - I don't think I should say any more here as it might spoil it for someone.