Different types of grout include cement grout, resin grout, and epoxy-based grout. You can use the same cleaning methods for different types of grout, though if you have colored grout it is best to avoid chlorine bleach. The best ways to clean grout include a baking soda scrub, oxygenated bleach, and vinegar.
One cleaning method that works on different types of grout is oxygenated bleach. Mix powdered oxygenated bleach with water, according to the directions on the package. Coat the dirty grout with the bleach/water solution. Let it sit on the grout for up to one hour and then scrub the grout with a soft brush or dishrag. The bleach should remove the stains from any type of grout. Rinse the grout with clean water.
One benefit of oxygenated bleach is that it won't discolor grout or turn everything it touches white. It also doesn't have the strong fumes that chlorine bleach has and is non-toxic. If you have white grout and aren't worried about damaging nearby carpeting or other surfaces, you can try to use chlorine bleach to clean the different types of grout.
Chlorine bleach will work especially well on grout that has a lot of mold or mildew on it. Combine one part bleach with one part water in a spray bottle. Spray onto the grout and let sit for half an hour. Rinse the bleach solution away to reveal clean grout. You may need to use a soft scrub brush for particularly stubborn mildew.
If you'd prefer a more eco-friendly cleaning method for different types of grout, try mixing vinegar with baking soda. You can also make a baking soda paste by mixing equal parts water with baking soda. Apply to the grout and then scrub clean. Another eco-friendly cleaning method for grout is to combine a cup of vinegar with one cup of water and then apply to the grout. Scrub with a brush or wipe clean with a sponge. Vinegar or baking soda work best on grout that isn't particularly dirty.
Always test the cleaner on a small, inconspicuous part of the grout before using it to clean the entire area. You want to make sure the cleaner won't damage the type of grout you have, particularly if your grout is older or damaged. If you decide to use a commercial cleaner designed for grout, make sure it won't eat away at the grout you have. Some acid-based cleaners will destroy ceramic grout.