I'm new to trying to clean and restore cast iron pieces and ran into a issue recently. A friend had a couple of pieces they found in their family cabin that I was going to try to get cleaned up. We had just assumed they were all cast iron but unfortunately the griddle seemed to be aluminum and corroded to bits after being in the lye bath. The reaction between the aluminum and lye also left a residue on the cast iron pieces I had in the lye bath at the same time. I haven't been able to scrub it off with just a sponge/scrubber and was wondering if anyone had any insight about where to go next? I am working on setting up an electrolysis tank and was hoping that would remove the it but I'd apperciate any other advice.