I've got some friends whose house is wall to wall saltillo tile. until recently, most of it was covered by carpet (no padding). The carpet wore out, got tossed, and the owners discovered underneath was brand-new-looking saltillo tile. The problem now is how to bleach, clean or refinish the saltillo tile that hasn't been covered, so that it will match the rest of the tile in the house. Is this possible, or is it easier to just rip up the worn tile and start over?