This little cleaning tip is a jewel. I personally use this on one of my shower floors. This particular shower floor tends to get mold growth faster than others. As founder of a Residential Cleaning Company, I understand bathrooms, ventilation, textures, various materials, rock, stone and tiles, drip pans, sheet rock. All are relative to mold growth. In between mold defense products, I use a cleaning agent of 1-part warm vinegar and 1 part dish soap. Spray on let dwell or sit for a 5 minutes and rinse and wipe. Clean and Pink uses vinegar but ONLY for certain jobs.