Dirt and debris can become trapped in between the grout, causing it to become dull and stained. Mold and mildew can also grow and stain the grout between your tiles. Stained grout can make the whole wall or flooring look old and dingy. Fortunately, there are a few methods that utilize common household items to restore the look of your grout.
Create a mixture of equal parts white vinegar and water.
Add the solution into a clean spray bottle.
Spray the grout with the vinegar-water mixture. Allow to sit for several minutes.
Spray the grout again with the mixture. Scrub the grout with a toothbrush. Add more vinegar-water mixture as needed.
Continue scrubbing with the toothbrush until the stains no longer are visible.
Put on a pair of rubber gloves.
Pour 3 cups of bleach into a large spray bottle, and then add 3 cups of water to the spray bottle. Swirl the bottle around to mix the contents.
Spray the grout with the bleach mixture.
Scrub the grout with a toothbrush or small scrub brush. Spray the grout again and allow to sit for several minutes.
Scrub the grout once again with the brush. Repeat Steps 3, 4 and 5 until the grout is stain-free.