Mix 1 part baking soda with three parts water. Combine the baking soda with the water in a small bowl or cup. Continue to mix it together until the baking soda absorbs the water and forms a paste. If your paste is too thick, add more water to it. If the paste is too runny, add more baking soda.
Apply the paste to the stains. Wear gloves and use your hands to smear a good portion of the paste over the stains on your shower. Target any discoloration or built up mildew that you weren’t able to remove from a basic cleaning. Cover the paste with plastic wrap. Tape the ends of the plastic wrap so it stays in place.
Don’t cover all the edges in tape so that the marble can breathe. Let the paste sit on your shower for 24 hours. The paste will dry and absorb the stain under it. When the paste is ready, it should be dry and hard. Remind people in the house that you are doing a deep cleaning and that they won’t be able to use the shower.
Rinse and wipe down the baking soda. Remove the baking soda paste from your shower by rinsing down your shower and wiping the stained areas with a rag. If you notice that the stain is still visible, repeat the steps until it is fully removed. Clean your screen with saliva. Saliva contains enzymes and bacteria that literally consume the dirt on the shower screens.
This is useful if you want to clean a spot where dirt is concentrated. Use a bleach solution to remove any mildew or mold. Mix ⅓ cup (80 ml) of bleach with 1 gallon (3.79 L) of water. Wear gloves and scrub the bathtub and the edges where the caulk used to be with the solution. Make sure that the room is well-ventilated. Use a stiff scrubbing brush to scrub the bathtub with bleach.