scotchbrite will work. you could also try an angle grinder with a wire brush on, or blast cleaning or some sort.... "sandblasting", but not done with sand (!).
i could see an angle grinder with a wire brush getting a bit out of control?
If you want mirror finish you want autosol. It takes forever though.
Yep, Autosol takes forever, works better on chrome. I found soaking the plates in Coke overnight worked ok.
Have used toothpaste on chequer plate brings it up a treat and smells nice too,also works well at cleaning up silver jewellery....![]()