Making homemade grout cleaner will reduce your exposure to the toxic chemicals in most cleaning products. Plus, it will save you money.
Fill a spray bottle with a half-and-half solution of vinegar and warm water. Spray on the grout, let it stand for five minutes, then scrub with the grout brush.
For more powerful cleaning cover grout lines with a paste of baking soda and water, then spray on the vinegar solution listed above. When the mixture stops foaming, scrub with a brush and rinse with plain water.
For tough stains apply Hydrogen peroxide straight out of the bottle to grout, or apply a paste made from baking soda and hydrogen peroxide.