If you have ceramic tiles, take extra caution when cleaning soap scum. Use a non-abrasive cleaner to avoid scratching the floor.
Cleaner
Using a non-abrasive cleaner is key. Spray it directly to the soap scum on the tiles and let it soak for 10 minutes before moving to the next step.
Wipe
After you have it allowed the cleaner to soak, use your sponge to wipe the surface. Repeat several times to remove all of the soap scum.
Rinse and Wipe
Once you are satisfied, rinse the ceramic tile surface and wipe it with a clean towel.
Source: www.DoItYourself.com