Worked great - highly recommended. Follow the directions.
In my case, I had cleaned a device with vinegar, working on a marble (I discovered) bathroom sink counter top. The vinegar (acetic acid) left dull splash marks over a wide area of the surface. I learned that these are not stains, but rather etching of the original polish. The product provides an abrasive of the right size and hardness to polish off the etching and establish a shiny surface again.
The instructions (or maybe the product details online) clarify that if you can feel the etching, the product can't fix the problem. I surmise that the etch in that case is deeper than the original polished surface. That turned out to be true for the one older spot which I could sense as grainy. But the rest of the etch marks were virtually gone after following the procedure. To be clear, the instructions direct us to use terry cloth and polish by hand. I admit that I tried a lambswool polishing pad attached to a drill, at at very low speed. This allowed more even and complete polishing over a wider area, but it could be risky so do it at your own risk. I still see some faint remnants of the etching, but am confident that if I go back over it they will be gone. There is plenty of product left in the jar.
Maybe one could guess at making a slurry of some abrasive and some carrier liquid and get similar results, but the risk of a bad outcome is way too high in my opinion.
Verified purchase: YesCondition: New