I use electrolysis to clean cast iron. There is no direct electrical connection between the two pieces (sacrificial metal and piece being cleaned) other than water. To make the process more efficient (which also rapidly increased the declining of the sacrificial metal or anodes)Sodium carbonate, Na2CO3, (also known as washing soda, soda ash and soda crystals) is added to the water. Both pieces are submersed in the solution, small positive charge attached to the anode, negative lead attached to the piece being cleaned. The piece being restored loses all organic materials and rust which gets transferred to the anodes. I suppose the point I'm trying to make with all of this is that no direct electrical connection is required for the chemical process other than the water.
