I really like our saltillo floors but...the grout is white and, the people whom we bought the house from did not take care of the floor. The grout looks disgusting and the tile has black scuff marks and other stuff that makes the floor look dirty and gross. I've tried everything and failed (grouting over the old, buffing, all types of cleaners, stripping and resealing). Despite all my attempts, my floor remains the same. What is the best route, remove all the grout and put new one or just retile? If I should retile, should I remove old tile or put new tile over old? Any type of help is greatly appreciated!