What is Soap Scum?
Soap scum is a white, chalky residue formed when soap combines with the minerals in hard water. It's tough to remove but not impossible.
The Vinegar and Dish Soap Trick
Mix equal parts white vinegar and dish soap in a spray bottle. The vinegar dissolves the minerals, and the soap cuts through the grease. Spray it on, let it sit for 15 minutes, then scrub and rinse.
Baking Soda Paste
For heavy buildup, make a paste of baking soda and vinegar. Apply it to the scum and let it fizz. Once the fizzing stops, scrub with a non-abrasive sponge.
Prevention
Switch to liquid body wash instead of bar soap. Bar soap contains talc and fatty acids that contribute to scum. Also, squeegee your shower walls after every use.