I have been watching a lot of his stuff and have recently read one of his books. Though I can't pick out specific effects, and would never know for sure, I have the supicion that he is a lot more pragmatic than one would think watching his TV shows. Keep your mind open, and I mean wide open, and you might find some "magic" effects that you could spin and present as hypnosis/mentalism effects. Also, watch his live shows, not his TV show, for inspiration. I am sure his live shows include a lot of pre-show work as well but I think there is so much in the TV show that you could really get confused and start "barking up the wrong tree."
I don't believe any of his live shows that I've seen contain pre-show work. At least the two "Something Wicked This Way Comes" and "An Evening of Wonders". I'm not as sure about "Enigma" because I haven't seen it as much, the same goes for his first special that I can't remember the name of. But you'd be surprised what you can make look like hypnosis/suggestion without actually doing it. So I suppose I'm somewhat agreeing with you and somewhat not at the same time lol.