Things You'll Need
You can let the oxygen bleach sit on the grout for up to six hours. Consider renting a steam extraction machine, which is very effective at cleaning grout. Apply a grout sealer for prolonged protection and easier cleaning in the future.
A new tile floor with clean white grout lines is a point of pride. But over time and after everyday use, the grout will likely start to look dirty and dingy. It's just a fact of life. You can restore the grout -- and your pride -- with a few household items and a bit of elbow grease.
Mix oxygen bleach with water in the bucket according to package instructions and for the amount of grout that you need to clean.
Pour the solution onto the tile so that it fills all the grout lines. Let it sit for at least 15 minutes. Check on it occasionally and add more of the bleach solution if it soaks into the grout.
Scrub the grout lines with a soft-bristled brush, such as an old toothbrush. Any dirt and grime should lift easily.
Empty the solution from the bucket and fill it with clean water. Dip a sponge into the water and rinse up the bleach solution from the grout. Allow the floor to air dry or dry with a towel.