Of all the thousands of reports I have read over maybe 10 years, I have yet to read a person becoming well from zappers. I think they are cute items and sound nice like all the other marketed products but overall they do not live up to the hype.
I and many others I know personally have tried them with no help. I think there would be a better chance by going to yahoo groups microelectricitygermkiller and spending the $4 to buy the materials. Those people report getting results.