Oh, and my batteries are technically 7.2v (although they say 9v), which makes a weak zapper weaker. This may help explain why I can use it so much without being fatigued. My other zapper fatigues me much more quickly.
I don't know that you need to use it as much as I do for purposes of Body Odor , but that's what I do (for a wide variety of things, and not just odor). You don't need to zap to get fenugreek's deodorizing properties. They work better without zapping. However, if you just ate too much and want to get rid of the fenugreek smell, zapping's a great way to do it.