what I learned: scratched toilets

Sometimes when trying to clear a clogged toilet, you might end up scratching the bottom of the toilet.  I'd recommend avoiding the risk of scratching the toilet.  Use a toilet auger with a protective vinyl throat or such.  But if it's already said and done, then Bar Keepers Friend will remove the scratches.  It turns out that this stuff is good for cleaning surfaces of glass, ceramic, copper, brass, porcelain, chrome, and stainless steel.