Marginally improved really abused sinks
The home we purchased has the original 16 year old black cast iron sink. You can see that it has a lot of scratches and the bottom is very dull from years of use. The cleaner polished & shined surfaces that that were still shiny (the walls of the basin), but did very little to improve the bottoms where the surface is dull. Still, it did provide some marginal benefit even for those surfaces.
Rating: 4 stars