So I seem to be having a lot of trouble getting my relics to get good contact due to the rust. Even when I take a file to it. I know it works because my sacrificial piece will decay away and my negative lead bubbles, but the piece attached to the negative never really gets great contact. I've seen some people drill a small hole and put a nail through it, but that's not an option.

You may want to try a different type of metal as the sacrificial piece. I find that stainless steel works just as good and doesn't corrode as quick...meaning less water changes.

What are you mixing with the water when you're doing this? For really rusted up relics you might want to try a salt water mix...but keep an eye on it, it may do more damage than good.

Well I've been using baking soda. I use stainless when I have it and while it decays, the relic doesn't seem to get any cleaner.