Bathroom grout is often overlooked during cleaning time. A quick wipe-down does not fully clean grout because the grout sits lower than the surrounding tiles. Regular cleaning helps to prevent stains and makes grout cleaning less of a chore. 1. Choose a bathroom grout cleaner. Commercial cleaning preparations are available. If you want to use an environmentally-friendly bathroom grout cleaner, mix white vinegar, 3 percent hydrogen peroxide and baking soda. 2. Apply grout cleaner to bathroom grout. If the grout is stained, leave the cleaner on the grout for two to five minutes before scrubbing. 3. Scrub the grout with a toothbrush. 4. Rinse the bathroom grout cleaner off. 5. Repeat cleaning and rinsing the grout if stains are still visible.