I have no experience at all in the use of hypnosis in any way, shape or form and thus cannot comment directly.

However, there is a site where you might be able to delve deeper into the subject. There is not a lot on it but maybe you can liven it up a bit with your questions and/or experience. It's web address is:

http://experts.about.com/q/Hypnosis-2206/hypnosis-classroom-foreign-language.htm

Good Luck

John