We have White Macuba polished quartzite countertops in our kitchen and we initially sealed them with DuPont bulletproof recommended by a contractor friend (our contractor/fabricator did not seal them). After noticing some rings we did research on Houzz and found a few threads (which I cannot find now) about people experiencing a similar problem with using bulletproof and people and professionals recommended using miracle impregnator 511. We used the miracle impregnator from our island which we have not sealed yet and it works great but now cannot decide for the rest of the kitchen counter which we have previously sealed with the DuPont do we need to strip it to seal it with the miracle important here or do we just sealed the miracle impregnator on top of the Dupont.