When I bought my SS cookware, I bought a can of Bar Keepers Friend to keep it nice and shiny. Well, I fried potatoes in my SS frypan and used that to clean the skillet. While I was cleaning the skillet I noticed it left some marks on my Kohl cast iron porcelain covered sink. I had tried everything to get those marks off before and it was a lot of hard work and still the sink looked bad. While I had the Bar Keepers Friend in my hand, I thought "Why not?" I sprinkled some of it on the black marks, took my damp dish cloth and .... swish, swish, the mark was gone. It took me about 5 minutes to clean the double-sinks and they were again sparkling white....try it, you'll like it! Besides, my SS cookware was also sparkling clean!