Our porcelain-enamel kitchen sink has developed stains, especially where the plastic "feet" of a "sink protector" have rested. I think that stuff that has been dropped into the sink and not rinsed away immediately has caught on those "feet" and remained there long enough to stain the surface. I have cleaned the sink from time to time with Soft-Scrub, but hat no longer seems effective, and now I find that the stained areas actually feel rougher than the unstained areas.
Any suggestions how to fix this problem? Any way to seal the surface?
Perce