Clean up spills right away. Letting cranberry juice or orange juice sit on grout for a few hours is a sure way to get a new stain. As soon as something is spilled on your floor, wipe it up with a wet rag, removing every last trace.
If a stain is left behind, pour a bit of hydrogen peroxide over it. Let it sit for a minute before wiping it away with a clean common marbleb tile cloth. Dry spills can also stain grout if they are left to be ground into the floor. Sweep up coffee grounds, clumps of dirt, and other solids soon after they are dropped.
Treat small stains regularly. To avoid having to do a deep cleaning floor tiles too often, treat small stains as they come. Use the same cleaning solution you would use for a deep cleaning, but employ a spray bottle to treat the small area you want to clean. You could also try an alternative small stain-cleaning methods:
Use a baking soda paste. Mix baking soda with a little water to make a paste, and then rub it into the stained section of grout. Let it sit for a few minutes, then use an old toothbrush to scrub it away.
Use white toothpaste. Squirt some toothpaste directly onto the grout in question, then rub it in using your rustic tiles finger. After a few minutes, use an old toothbrush to scrub the area. Wipe it up with a clean wet rag.
Use a pencil eraser. For the smallest stains, a pencil eraser does a surprisingly good job. Choose an eraser that is white, rather than stained a different color, or you may end dyeing your grout the color of the eraser.