Ah my friend warned me of something I missed - that electricity follows the shortest path, so of course... that casts doubt on whether tapping a battery on your arm would work! He also said that ofc even opposite hands would make the most obvious circuit - up your arms and across your upper chest/shoulders. How is it that the zapper seems to get further? I'm considering putting one of the copper pipes under my foot and holding the other in my opposite hand! lol
EDIT -- Or perhaps I'll just buy a small sheet of copper to be a foot pad :)