This is not true at all. There is a common myth that once a hypnotist places someone into a trance, they have complete control over that person. We see this in stage shows where participants are apparently so subjectable that they start acting in an embarrassing way. Hypnotists can’t make people act like a chicken against their free will. Instead, subjects are in control of their actions and thoughts and are simply guided by the hypnotist.
This is another myth where cartoons and popular culture have skewed the reality of hypnosis. Authentic hypnotists aren’t going to wave a watch in front of someone’s eyes and get them to repeat every line they say. Hypnosis doesn’t rely on this sort of up-front suggestion. There are no aggressive, bullying tactics here. Instead, hypnosis relies on many post-hypnotic suggestions to help subjects deal with the issues and thought patterns. Ideas fed to people in trance work in the unconscious long after the session.