Just wanted to share with everyone the good experience I had with Aqua mix nano scrub. It claims to remove sealers and coatings. I Have a client with a tumbled travertine that had patches of an old coating. I used nano scrub with 220 brushes and the remainder came right off real easy. I tried a section without the nano and did not get the same results. Overall I was quite impresssed. with the performace of this product.