· the baking soda will help remove tough stains and hard water buildup, while the hydrogen peroxide will clean and brighten, cutting through residue on the grout to remove discolorations. · hydrogen peroxide and baking soda can be combined into a paste used to clean grout. Spoon the homemade grout cleaner onto the grout lines and allow it to sit for around 10 to 15 minutes. The bubbling action helps lift deep stains. Choose from a wide range of building materials, available at amazon. Apply directly to stained lines and let sit for at least 15 minutes. Spread the mixture over the grout and wait 5 to 10 minutes. Baking soda and hydrogen peroxide. Apply the paste to grout lines, let it sit for 15 minutes, and use a toothbrush for applying and scrubbing. This tutorial will walk you through how to clean grout with a diy grout cleaner. Get deals and low prices on grout whitener and cleaner at amazon. If youre working in an area where grout is exposed to grease (like in the kitchen), add a few drops of dish soap. · combine ½ cup (136 g) of baking soda with 1⁄4 c (59 ml) of hydrogen peroxide and 1 tsp (4. 9 ml) of dish soap. Combine 1 part hydrogen peroxide and 2 parts baking soda in a bowl to form a paste. Create the peroxide paste: Work the paste into the grout with your brush. Mix baking soda with 3% hydrogen peroxide to form a slightly foamy paste. · make a grout cleaner paste of two parts baking soda to one part hydrogen peroxide. Not to worry, there is an easy way to whiten grout , and you only need two ingredients: