I am getting ready to reuse a set of Cometic head gaskets that are coated with Copper Coat. How is the best way to clean them without hurting them? I have them soaking in my parts washer now. Can I just use Scothbright? will brake cleaner hurt them? I am also planning to use them on the same block, but with a different set of heads. I will be going from iron Stage IV's to alum. Indys, is this OK?