But if you want to experiment with that then you have to measure your own body and see which side is more positive than the other, and then do 2 tests- one with positive from the device going to the positive side of your body, and one test with the positive going to the negative side of the body.
Beck couldn't of said that about the signal not crossing zero meanwhile he was promoting blood electrification that did just that. Maybe you misunderstood what he said.