Australia's version of "The Mole" had their own version of the Milgram experiment. The "toughest" of the lot was taken away and secretly given impromptu acting lessons. The group was taken to the location and shown the tough guy strapped in a chair. The group had to answer twenty questions to add money to the pot; but every wrong answer increased the shock level to be endured by the tough guy. If the group decided to stop the game before getting to 20, the tough guy won a free pass to the next episode.
As a hoax, I thought it was just barely above the level of bad taste (the tough guy came out, looked around, asked why everyone was so concerned and revealed the hoax, and the group moved on to whatever was next) and I really don't see a way you could do that sort of thing more than once, especially after people have seen the show.
