company, who cleaned and sealed my tiled las week. His instructions were, use a string mop, but, one of those that has foam strings, two buckets of water. One with a Mr. Clean like cleaner and water in it, the other one just plain warm water. Dip the mop in the Mr. Clean solution, mop the floor, rinse the mop in the plain water, go over the floor with the plain water mop. He says the dirt gets into the grout, and when you mop it, gets caught in the grout. So with going over it with clean water will remove the dirt left behind by the mop. The steam mop, he says ok to use, but not often, that the steam will harm the grout.