Using caustic cleaners like bleach or acid can show short term results, but in the long run they will leave your grout and natural stone looking dull and dirty. This river rock floor was damaged by too harsh cleaners and started to look hazy and dull. In order to restore the natural stone we deep cleaned the floor with a mild alkaline cleaner and stiff brush. Then, with the application of a restorative stone sealer we were able to bring back the wet look and visible grain of stone.