While it may be true (note may be) that you cannot be hypnotized to do something that is against your will or conscience, because hypnotism is simply a form of powerful suggestion, you could be put into a mental situation where you would do something immoral,
for example, you would normally not simply strip down in front of people, but if you were convinced in a hypnotic state that you needed to get ready to take a bath, you might.
I believe that the Church is opposed to it unless for medical reasons. The reason is you are granting part of your God given will to someone to manipulate.
A lone Raven