Well...it may be back to the drawing board for me. It turns out the graters are stainless steel plated and not pure stainless steel and that is why the part where they were discoloring are now rusting and that may be the red scum I found after the 3 baths. Though, there was no scum when I did a footbath with 1 T. salt instead of 2 and the current went through the graters the same. Just thinking on line. The graters are still steel and conduct the currents, they're just not pure stainless steel. My son suggested using copper but I don't know how safe that is or what the outcome would be. I can get pure stainless steel rods from a scrap metal place near me but it would be nice to know that the graters are still beneficial as is.