I tried it once at a corporate thing. It was a mass hypnosis event and our hypnotist explained that you cannot hypnotise someone against their will. Basically it was like drinking a couple of shots of vodka and feeling very relaxed. When he suggested something, my mind would be like "why not, no harm". But when he started suggesting things that I didn't want to do, I was able to resist.
Everyone does respond differently though so who knows.
