IF "it should be battery operated" was your due answer by fear to lawsuits I'm less worried about a thunderbolt or some short circuit that would make the device to melt in such a way that would make current from the grid or the thunder to reach me, than being abducted by aliens.
I already got a frequency generator for a fraction of what a multi-frequency zapper costs, and it's very accurate :)
PS: Your "Also, see" link tag was unclosed (or escaped) and the whole reply form ended up inside it, looking like an invasive redirector.
If you got this is because I fixed the code in my browser and I was able to send it.