I used the 303 (tire/rubber protectant) on my steps, and it looked pretty good.
But after a week or so it was back to looking the same - dull and scratched up.
So I replaced the rubber treads with Tile. It's easier to keep clean and won't wear out.
It's not hard to do tile (hardest part is finding a tile that "matches" the interior tile), pull off the rubber tread, clean the residue, and lay the tile like you would in a home. You can tile the riser too, but I put polished stainless steel on the risers.