Hi, I'd like to help you with your question.
Whether or not hypnosis is effective in helping agoraphobia depends on the person. Every person reacts differently and some people have personalities that allow for easy hypnotizing and others do not. As far as I know, there are no specific case studies showing the effectiveness of hypnosis; however, this does not mean it does not work.
Hypnosis can help a person with agoraphobia learn to relax. This in and of itself is a big step in helping the person overcome how they feel. Relaxing your body when faced with your fear is an important part of recovery.
Any type of self help work is effective as well. Here are some resources to help:
The Anxiety & Phobia Workbook (New Harbinger Self-Help Workbook) by Edmund J. Bourne
The Cognitive Behavioral Workbook for Anxiety: A Step-by-Step Program by William J. Knaus
From Panic to Power: Proven Techniques to Calm Your Anxieties, Conquer Your Fears, and Put You in Control of Your Life by Lucinda Bassett
Relieve Anxiety with Medical Hypnosis by Steven Gurgevich
You can find these resources on Amazon.com or your local library may have them for you.
In any case, hypnosis is worth a try. In overcoming agoraphobia or any type of anxiety based problem, the effort and the determination in trying different therapies can only help you feel better. Keep pushing forward and trying what you feel could help you.
I hope this helped,