When tile is installed, grout is applied to fill the cracks between the individual tiles.Tile grout is similar to cement. In the process of applying the grout, some inevitably winds up on the surface of the tile. If the grout is not removed when it is wet, it will bond to the tile and is harder to clean off. But dried grout is still fairly simple to remove from a tile surface with the right tools and procedure.
Scrape the dried grout off of the surface of the tile using a flat-bladed scraper. Hold the scraper at a low angle to the surface of the tile to avoid scratching or gouging it. Use short, jabbing motions around the edges of the dried grout until all the raised areas of grout have been removed.
Soak an old rag with white spirit and scrub the tile where the dried grout was located. The white spirit will remove any residual grout from the surface of the tile.
Fill a gallon bucket half way with warm water and put two or three squirts of dish soap in the water.
Wipe the tile with a sponge dipped in the soapy warm water. Most dish soaps contain a degreaser that cleans the tile of any residual white spirit and grout.