Use a light drill if you have a lot do. I used them to clean my mother's kitchen an bathroom. In no time at all the coffee stains, soap scum, spills were gone. I cleaned them with soap and water, and dried them out. I plan on ordering more of them for my house.

Brilliant. I love having a super clean house but don't have the time to get it that way without innovative contraptions such as this one. Made cleaning the shower and tub into a 30 minute job rather than a 2 hour process. Going to use it to deep clean the grout on my kitchen floor next.