Don’t use vinegar on marble, travertine, or granite. [3] X Research source
Adjust the ratio of sugar to warm water until you have an effective mixture. Alternatively, you can apply undiluted vinegar to hardened grout to make it easier to scrape the grout off of your tile. Once the grout is removed, rinse the entire area thoroughly with plain water to remove all of the vinegar.
Try this method on grout that has not set for long. Don’t wet the sponge or cheesecloth or the dust from the grout will stick to the floor again.
Wear gloves when cleaning with bleach. Open a window or wear a respirator to protect your nose, throat, and lungs. Protect your eyes with safety glasses. Wear old clothes that can get bleached.
Scrub with any coarse salt, even Epsom salts. You can use the same method to clean your grout with Borax. Put a damp scrub brush in a bowl of the Borax and use that to scrub the grout.
Use water if you don’t have lemon juice.
Look for hydrochloric acid if you can’t find muriatic acid. They are the same thing. Don’t add water to the acid or you might cause a dangerous reaction.
Don’t mix hydrogen peroxide with bleach.
