Cleaning grout is a necessary chore. While there are many cleaners available on the market that boast about being able to clean grout and anything else, the price tag can be a bit much. All you really need is a couple of inexpensive items you probably already have around the house.
Dampen the area with a soft, clean, damp towel.
Sprinkle baking soda all over the dampened grout. The moisture will help it to stick.
Allow the baking soda to sit on the grout for 10 to 15 minutes.
Dip an old toothbrush in hydrogen peroxide and scrub the grout with it. The baking soda will act as a mild abrasive and help to help to clean stubborn areas.
Rinse the area with clean water to remove any dirt, debris and baking soda.