Anything you can do with hypnosis, you can do without hypnosis by talking through the changes as if they are just the natural extension of the everyday - nudging the envelope of the possible out, one bit at a time. But, it's quicker to just do the "impossible" and jump outside that envelope altogether - just cross the line into the "hypnosis" envelope, which tends to include more powers. Or better yet, jump past the "hypnosis" envelope. Without anticipations to guide them, they can't really reject suggestions.
"Convincers" can help you cross that line. The idea is to link easy pieces together into bigger things that people will predictably rule as "impossible". For example, you can play imagination games with someone and then next thing they know, their hand is absolutely stuck to the table. This is the point where they realize and alieve that they are very hypnotizeable - which can be a pretty big shock to their worldview. If they were so wrong about hypnosis not being able to do this, they can't really feel sure in saying there is anything that it can't do. Anything is possible at that point. That's why convincers are so cool.
However, a stuck hand doesn't always get them to jump the fence because their line could be drawn elsewhere - especially if you don't present the hand stick as some mind blowing feat. For instance, I recently worked with someone who "forgot" how to be a good subject. Or rather, she got kicked into a negative expectancy spiral. Luckily, expectation ain't everything.
I fought my way to get some hypnotic suggestions to work, but only in the "nudging the envelope" way. I got her arm to stick, but in her mind, that wasn't enough. Her previous experience with hypnosis led her to redraw her line a few steps past the arm stick.
So what I did next was utilize the responsiveness I had so far to get her to really get into this "game" we were playing, where she would "pretend" that she had amnesia for the last bit that we did. Of course, she did a very good job - and forgot about the part where it's just pretend - after all, it's not important to track that bit of information, we're just playing a game ;). I then pushed her more and more to defend the proposition that she wasn't playing along. Once she was really entrenched there, I got her to agree that if I could show her that she actually was missing time in her memory, then that meant that I had already gotten her to "send her conscious mind away" - which she viewed as breaking back into the "legit hypnosis" envelope. Once she agreed, I gave her back the piece of memory that she was missing time - and not the trick behind how I did it. Now she has access to the full range of hypnotic phenomena again.
Figure out where they draw the line, get it carved in stone, and then cross it.