How you clean grout depends on what type of flooring and grout you have. For most homeowners, a scrub brush, white vinegar and a paste made of water and baking soda does the job. If you have white grout, however, you can use hydrogen peroxide to help bleach the grout and make the scrubbing easier. Those with natural stone tiles have the toughest job, because natural stone should never be cleaned with a scrub brush -- scrubbing could cause permanent damage.
Colored Grout: Step 1
Gather together the items you will need to clean your grout. These items include baking soda, white vinegar, water, a scrub brush and a sponge.
Colored Grout: Step 2
Pour just enough water into your baking soda to make a paste and then spread it on the grout with your fingers. Really push the paste into the floor with your fingertips so you get it into the grout and not just on top of the tile. When the paste is on the floor, use a sponge to squeeze some white vinegar over it. The vinegar will start to foam and bubble when you do this.
Colored Grout: Step 3
Wait until the vinegar and baking soda paste stop foaming and bubbling. This should only take about a minute. When the foaming stops, use a scrub brush to work the paste and vinegar into the grout. This will loosen and lift the dirt, which you'll see as the baking soda mixture starts to take on a brown or gray color.
Colored Grout: Step 4
Rinse away the baking soda and vinegar with a sponge and warm water. If you are doing a large area, you can use a mop and bucket rather than a sponge.
White Grout: Step 1
Collect some water, hydrogen peroxide, a scrub brush and a sponge.
White Grout: Step 2
Combine water and hydrogen peroxide in a 50/50 mix. Sponge or spray the mixture onto the grout, and let it sit for a few minutes.
White Grout: Step 3
Scrub the grout with a scrub brush to work the hydrogen peroxide and water mixture deeper into the grout.
White Grout: Step 4
Rinse the hydrogen peroxide mixture away with clean, warm water to reveal whiter grout. If your grout is still stained, make a stronger mixture of hydrogen peroxide and water by increasing the amount of hydrogen peroxide, and repeat the process. Some stains simply require more bleaching power than others.
A Word on Stone Tile
Make sure that you do not use a scrub brush on grout between natural stone tiles, because the stiff bristles may damage the stone. This includes slate, travertine, marble and granite. Instead, dab a 50/50 mixture of white vinegar and water onto the grout; let it sit for a few minutes, and then rinse it away with a soft cloth. If that fails, purchase a special stone cleaner at your local hardware store and use it according to the package directions.