I have had some success with zappers especially after the OB has started. I once put the zapper at the bottom of my spine/tailbone and could actually feel the current going through the OB area. It seemd to heal more quickly that time.
I think they can be effective but without all the health protocol in place, they are not AS effective (or effective at all) in my experience. I recently made a post called "thanks and what has helped with me" which has some info about blood tonifying.