The best grout cleaner is Clorox Toilet Bowl Cleaner with Bleach.. There really is no trick to doing this. Simply take your Clorox cleaner (its a gel, so it pours perfectly into the grout lines) and pour it onto about a 3 X 3 foot section of tile floor. Let the cleaner sit on the grout lines for approximately 10 minutes. Then take a hard plastic bristle brush and lightly scrub the cleaner into the grout lines. It doesn't take a lot of effort, the cleaner really does most of the work. Let…