I know for a fact someone can. For several years my parents had a hypnotherapy practice. The way it works is to relax someone to a point where their waking mind is just about asleep allowing their subconscious to come out more. In other words it is a form of meditation.
Also there is such a thing as self hypnosis and there are times that people have even hypnotized themselves. For example if you have ever been driving on a road you have done many times and then realize that you are there yet realize do not remember most of the trip there just as you are getting to your destination? This "road hypnosis" is a bit of a trance meditation.
Finally as for those stage show guys who hypnotize people most of them are fakes. It is possible to hypnotize someone quickly like that but to do so they would have had to hypnotize them before making the people that go on stage almost like plants. Also for the few that do hypnotize people on stage that quickly they are looking for people who are willing to be hypnotized because to be hypnotized you need to want to be. So their finding willing people makes it easy to pull them into a trance.