"Used to paint over old, stained grout. It's now a nice bright white again! Definitely time consuming, but was worth it in the end. However, the bottle says to remove excess that got on the tile with a nylon scrubbie, but that didn't work for us. Credit card didn't work either, nor plastic spoon. Metal spoon did, but that left a black mark along the edge of the tiles. We have smooth, glossy tile so a razor blade ended up working perfectly. Just zipped right off! This removal method may not work on non-glazed tile or non-smooth tile though."