The aluminium ones with the Fisher badge. Mine are nasty - I was thinking greenie and dish soap? Finish them up on a buffing wheel?
I cleaned a set with wheel cleaner and polished. But have to say later on i replaced them. For $55 a set much nicer.
You really can't clean them that well......they are anodized aluminum so it's not like you can rub out scratches, etc like you could if they were bare aluminum. Buy a new repro set if you want something that will look new.
It forms a hardened layer of the aluminum on the surface. You have to remove that layer to get to unaffected virgin aluminum and then start sanding and polishing, etc. Likely to little effect with all the ribs on the moldings. Not remotely worth the effort considering the cost of new moldings.
I use simple green and a brass brush to get the gunk off. Then put it to the buffer, but you got to stay away from the fisher badge unless you want to try and repaint it (which i have done, but it is a pain in the butt). You can order new badges, but they want money for those. If it is really discolored, lot of nicks, etc., you have to do some sanding first.
Did that to mine, then polished them up bright and shiny 3-4 years ago. Still look pretty decent, not as bright as they were when I finished (a little milky now). However, they were pretty skanky when I started, so it is still an improvement. Old boy down the road from me got 50 or so old chevelles in his pasture and I went through and gathered up some sill plates off those (got 3-4 pairs). They all look pretty ruff after all those years. You can try just cleaning if you don't want to mess up their coating, but they still might not look too good. If you want it to stay shiny, you could always shoot a clearcoat over it. You can always buy a new one for $28 https://www.ebay.com/itm/Door-Sill-...822234&hash=item4443941ea4:g:RSEAAOSwKjFdV~im but you got to buy the fisher plate separate or transfer you old one.
