I've seen hypnotist travis fox perform at the fair, he's always a great show. not sure if his hypno-self-help cds work, but personally that's what i'd be most comfortable trying.
i'm not entirely sure the psychedelic state is 'suggestible' like hypnosis requires. it seems like the increased perception and awareness of details would make hypnosis difficult. then again, if one is well-experienced in the 'letting go' of psychedelia perhaps that may help.