Combine the hydrogen peroxide and water in a sprayer bottle and shake to combine.

Sprinkle Oxygen Boost over your grout lines.

Spray the hydrogen peroxide and water mixture to wet the grout lines.

Scrub the grout lines with a small brush (an old toothbrush works great) until clean.

Wipe the grout lines clean with a damp washcloth.

Once you're finished with a good section of the grout, mop the floor using a homemade mopping solution.

Let the floor dry, and then sweep (or vacuum it) to get any residual Oxygen Boost up.