Snake oil:
Great an experience, but no benefit, just hooey.
http://www.holotropic.com/about.shtml
"The process itself uses very simple means: it combines accelerated breathing with evocative music in a special set and setting. With the eyes closed and lying on a mat, each person uses their own breath and the music in the room to enter a non-ordinary state of consciousness. This state activates the natural inner healing process of the individual's psyche, bringing him or her a particular set of internal experiences. With the inner healing intelligence guiding the process, the quality and content brought forth is unique to each person and for that particular time and place. While recurring themes are common, no two sessions are ever alike."