Hypnosis is not something I have ever investigated. From what I have seen, it falls into the marginal area. By it's nature it is very hard to test, it is grounded in personal interaction in a way that makes blind testing nearly impossible nor is there any way of directly measuring it's effects on the mind.
There is a consistent enough effect that there has to be something there. But without any complete theory of what it does or how it works or any way of directly measuring it's effects it is relegated to the borderlands of science.