I have put people in a hypnotic trance. Or, more accurately, have helped people allow themselves to go into a trance.
Let me explain my viewpoint:
There is NOTHING magical about hypnosis. It's all focus, imagination and positive reinforcement. I explain it to others like this:
If you've ever been to a movie, or have read a book and have gotten so into the movie or book you almost forget you are in a theater, or have forgotten the time, or people say "Hey!!" several times before you respond. Or if you've been driving a familiar route and it's a long drive. Suddenly, you look around and say to yourself "Wow! I'm here already???"
All of those are exactly the same kind of a "trance" as a hypnotic one. Just concentration and focus.
People do what is suggested to them in this concentration simply because a) they want to. b) they are focused on the task given to them.
There's no magic, you can't make any appendage bigger, can't make you remember your past lives, etc. However, if the subject really wants larger appendages or wants to believe they're abducted by aliens, then the hypnosis will convince them that their "memories" are true. But then again, any cold-reading "psychic" can do the same thing.
As to helping people lose weight or stop smoking, the trick to make that work is to keep reinforcing the hypnosis and giving positive reinforcement whenever the subject does the desired behavior. If the subject doesn't do the desired behavior or does something wrong, then you still do a hypnotic session but there is no reinforcement. This is called conditioning. We, as individuals, do it all the time.
Now there are many different ways to achieve this focus. None of them are magical, all of them are easily explained away if you've studied your basic college psychology, and all of them are ways we do it to ourselves naturally.
I'm basically saying that there is a state of mind reached, but it's simple intense focus. Nothing magical or paranormal. Nothing to try to prove the million dollar challenge, because, quite frankly, it's all easily explained away and nothing really special happens.
In fact, by reading this post, technically you were in a hypnotic trance.

See how easy that was?