To remove coffee, tea, wine, or soda stains from bathroom counters or tubs, add WD-40 to the marks and wipe them off with a damp cloth or sponge after a few minutes.
To remove hard-water stains from glass shower doors, spray the entire surface with WD-40, wait for 15 to 30 minutes, and wipe it away with clean microfiber towels.
To get into the narrow grooves of dirty cement tile grout, aim the slim straw nozzle of your WD-40 can at the grime and rinse it with soap and water after a few minutes.
Spray scuff marks on tile and vinyl floors with WD-40, wait a few seconds, and wipe it off with paper towels using a circular motion. Clean the oily residue when done.
Spray bathroom mat and runner stains with some WD-40, wait five minutes, and wash. You can use the machine or clean them by hand using detergent and rinse with water.