Review on Pack of 2 Maryton Pumice Stones with Handle - Effectively Clean Toilet Bowl Rings and Hard Water Stains (Gray) by Charlie Conner

The stone copes very well with very heavy deposits in the toilet. I've tried vinegar and baking soda and they did nothing to remove it. The stone wears out significantly, but this is more of a plus than a minus. This allowed me to place the stone in hard-to-reach places on the bottom of the bowl. The only downside I've found is that it's difficult to get to the curved hole area on the bottom. After removing the deposits, the surface of the bowl became very smooth. I did not find that it significantly scratched the porcelain. I recommend the product. I would buy this again.