I have been treated with hypnosis both with a CD and in person and I would definately go with the CD.

In person I found that I would fall asleep in every session, whereas the CD it was like you described, sometimes i fell asleep but other times i felt i was 'under'.

I have read somewhere that it takes 6 weeks to change something from being an effort to a habbit. So if you can listen to it for 6 weeks you should have embedded the information and changed your eating habbits alot. Then maybe you can just listen to it once in a while as a catch up.

Good luck!!