Since a sink is a plumbing fixture, I have before and after pics of my sink. First pic was taken after I used lysol and a rough sponge and scrubbed as hard as I could but this was decades of crud. 2nd was after a few coats of baking soda & vinegar with some salt for grit, elbow grease, lots of swearing, and eventually some pumice stones (found in nailcare area-- which I had to ask for directions to find in the store).