Cleaned my exhaust...
I have a custom stainless exhaust thats a crossover that eventually leads into one 2.5" pipe that exits cowling. With the oxidation, it was pretty unsightly because you can see it with the cowling on.
I was considering an order from Vetterman, even called Clint, because the heat muff was horrible mess of failing fasteners and RTV.
I thought about sanding things down, but when removing the old heat muff I tried lightly sanding/buffing the oxidation out without success. Even 80 grit flapper wheel on angle grinder had a hard time on oxidation..it just seemed to polish.
I little search of the triple-dub revealed that motorcycle enthusiasts will use acidic based toilet bowl cleaner to remove oxidation staining...just happen to have some muriatic acid lying around to give it a try. This, and 220 wet/dry, made short work of the oxidation.
I initially used red scotchbrite, which also worked, but the acid ate through it so I switched to sandpaper.
Looks like it's freshly extruded...you can compare difference in the pic below.