If they have al ready had a high polish put on them. Do not touch with never dull. Ya be sorry. If ya had alum that has never had polish work on them. Never dull is a good start. But the wool fibers will make it look like ya sanded it with 1000 grit sand paper. I did a spot on a tunnel ram with a mirror shine. I was mad after. And had to have it redone/touched up
Mother mag wheel polish a old t shirt and elbow work. Will make huge differance. If your still getting black. Then it's still pulling dirt out of the pores of the metal