Done! The two bolts/screws are solid brass, and each connects to one of the two mesh grids inside. There is no short circuit, at least so the multimeter tells me, and I have a good connection between each bolt/screw and it's respective grid. The next test is pressure testing (local water pressure can get up to 100psi at times), and then to run a current through it. I'll have to get some sort of flow sensor to regulate the current flow, I don't want pockets of hydrogen and oxygen building up in my water pipes.