I certainly don't think hypnotherapy is a cure, but it can be another "tool in the toolbox" in helping to cope with this condition.
I have heard of a couple of people trying it with mixed results. If you are serious though, I'd be sure to ask them if they have any experience with CRPS or at least chronic pain. Don't want to get the guy that makes you sing like Elvis Presley or act like a chicken when you hear the word APPLE
The mystery of the way pain works in the body is a little different with every one of us as is the ability to manage it in different non-conventional ways like meditation, hypnosis, etc.
I like to keep a very open mind and am open to trying most any (non-invasive) techniques to help me get through the day.............
Here is a link from the University of Minnesota which has some pretty good information on some things that might be helpful. Click on the link, then look down at the bottom where it says "healing practices A-Z" and explore some options, some of which I use daily.