I've seen stuff that definitely made me believe. A stage hypnosis fella's performance was ruined by a girl whom was so susceptible to being hypnotised that after he 'put her under' once, just the sound of his voice made her go into a trance.

He sent her out of the hall, to go and sit outside. She heard his voice through an open window and passed out. He had to cancel his show and spend the rest of the evening trying to sort her out! Was bizarre to watch.