Lemon juice removes soap scum and stains from surfaces due to its acidity. The acidity is mild, so it doesn't damage or etch most surface. Lemon juice also has mild bleaching properties that help whiten dingy grout. Baking soda primarily provides an abrasive that scrubs away the scum and dirt loosened by the lemon juice. Using the two ingredients together results in a natural cleaning product that can clean most stains from the grout between tiles in your bathroom or kitchen without causing any damage to the surface.
Things You'll Need
Brush or rag
Squeeze the juice of one lemon into a measuring cup. Strain the juice through a mesh sieve, if necessary, to remove any seeds or pulp. Alternatively, use 3 tbsp. of bottled lemon juice.
Add an equal amount of baking soda to the lemon juice to form a paste. The paste should be slightly thinner than toothpaste so that you can smear it onto the grout easily. Add additional lemon juice to thin the paste to the desired consistency, if necessary. To thicken the paste, add baking soda 1/2 tsp. at a time.
Coat the stained grout with a thin layer of paste. Allow it to set for five minutes so the juice can loosen the scum and grime.
Rub the paste into the grout with a soft scrubbing brush or rag. Rinse with clear water.
Repeat the application and scrubbing a second time, if necessary, to remove any remaining scum.
Test homemade cleaners in a small area first to ensure they don't cause staining or damage to the grout surface.