As a former cat owner, the idea of using anything with the words "high voltage" emblazoned across the box near my pet gives me pause. Sure, it's only a couple of AA batteries, but you should see what they can do with transformers these days. Even the description refers to "high voltage supplied by low voltage", and something about "removing the deciduous hair from your pet."
I'll tell you what, you go first. I'll stick with the safer looking gadgets for my own pets.