I do know my hammer keeps my nem at bay. They have touched a few times and it seems the nem shrinks up a bit. In my hammer's defense, it's bigger then the nem and when its open, it's about 5 1/2" (single head) and the thing is just HUGE. but you're right, pretty much everything else loses to the nem.

I too was kind of shocked but the nem zapped me on the back of my forearm, stung like **** and I had welts. I just know now to not stick my hand in the tank near it....lesson learned. It's a GBTA that Im talking here.