1) What is Hypnosis is?
There are many definitions for this!
I) An altered state of consciousness and heightened responsiveness to suggestions.
II) "Being open to suggestions"
III) trance-like state which resembles sleep and is artificially induced (characterized by an increased susceptibility to suggestion)
IV) a state that resembles sleep but that is induced by suggestion
v) Hypnosis is a mental state (state theory) or set of attitudes and beliefs (non-state theory) usually induced by a procedure known as a hypnotic induction
vi) A state in which a person is awake, alert, and focused, and has a greater susceptibility to suggestion.
VII) Psychological condition of altered state of consciousness in which some people may be induced to show various differences in behaviour and thinking, like heightened suggestibility and receptivity to direction.
VIII) A Hyper-suggestible state, providing access to the subconscious mind.
SO YOU CAN PICK ANYONE AS MY DEFINITION! I like all above 
Sometime one session is enough for treat, But sometimes it takes several. It depends on situation. You will experience it, when you get more clients.
Anyway you have helped 4 people by now with Hypnosis. It's a good thing for the hypnosis field. We must thankful to you.
This is protract & time consuming. I have a big project & must work on it. If I spend much time in here, I loss my time.
Good luck!