hypnosis

Has anyone used hypnosis to quite smoking and been successful?

On of my frineds used the 'Staying Stopped' Resolution Reinforcer, that can boost unconscious determination to quit. He listened to it during the quitting process.

My sister have had the hypnosis done and she quited for almost a year after it, so it worked for her. But now after she had stressful situation at work she started smoking again.