Soap scum is a residue created by hardness in water reacting to the fat content in soap. Prevent soap scum by using liquid bath or shower soap as opposed to bar soap which dries into a solid and forms scum. Wax your shower walls periodically with car wax to help prevent scum from adhering. If you already have a layer of soap scum that needs removal, any method that dissolves fat works to clean away soap scum.
Apply lemon furniture oil on a plastic scrub brush or nonscratching abrasive pad to remove soap scum as well as prevent future build up. Scrub in a circular motion. Wipe the scrubbed oil and soap scum off with a soft cloth. The oil residue that is left will prevent future soap scum from accumulating.
Mix baking soda, a natural abrasive, with water to form a paste and then use it to scrub away soap scum. Rinse when done, then clean the baking soda out of your drain with a cup of white vinegar.
Spray white vinegar on soap scum and let it sit. White vinegar is 5 per cent acetic acid with a pH of 2.4, making it a safe, nontoxic cleaner. Because the acetic acid is so diluted, the vinegar needs time to sit on the soap scum to be effective. Using a plastic scrub pad or brush, scrub away the softened soap scum and rinse. If you have trouble with vinegar running off the soap scum when you apply it, try drenching a paper towel and laying it on the scum to soak.
Don't mix cleaners that contain bleach and ammonia together because toxic fumes will result.