I have rubber stair treads on my back entryway steps. They are black rubber
with many ribs on each tread(very very narrow space between each rib). They
are in excellent condition but although I vacuum and mop(with ammonia
solution) them often, they never really look that good.

I am going to be repainting the wood portion of the stairs and would like to
have the rubber treads look a lot better than they do. Removing them and
going to new ones is not an option, so any ideas about how to clean them,
restore them,etc would be much appreciated.

Thank you,

Bob