Sudsy Ammonia and some elbow grease. Nothing better and cheaper than special cleaners that tile places will state work better than the other company. Just beware that using Ammonia to clean the floor, that if you do not rinse it completely off the tile and grout, the salts in it will bleach the grout color. You can get grout stain to restain the grout back to the original color, but tiles like Travertine tend to soak the stain into it, so you really have to be cautious.Is there a chemical solution to use, whats the best way to apply it?
thx