With the knowledge that bacteria like E-coli and C-diff can be transferred from shoe to floor and vice versa, it is extremely important to make sure our floors are as clean as possible. So we mop, on the small scale, or use a scrubber, on the large scale. In both cases, making sure the equipment is clean keeps our floors clean, instead of even more contaminated.

Mops are pretty simple tools and do the job well if we use them correctly. They should be cleaned after every use. That means, if the head is removable, take it off and toss into the washing machine with the hottest temperature and add bleach. If the head is permanently attached, soak it in very hot water with some dish detergent. Make sure to let it dry completely and store it with the head up, not laying on the ground soaking up more contaminants. If possible, vacuum the area first to suck up as much debris as possible. Then use hot water and a good quality cleaning solution. While mopping, there is a certain amount of filth being redistributed. However, the majority is being picked up by the mop. So rinsing the mop often is key. And there is only so much a cleaning solution can do. So, if mopping a large area, emptying the mop bucket for fresh hot water and cleaning solution, is a good idea. Otherwise, the mop water is just adding to the problem.
Remember too, the longer a mop head is allowed to dry after heavy use, the greater the chances that it will be stained, making is appear dirtier than it actually is. Some chemicals can also damage fibers making them lose color. So don’t assume the mop you are using is ready to be thrown out due to discoloration. If proper cleaning has taken place, just test the mop head by wringing it out in clean water. If the water remains clean, the mop head should be fine. If dirty, it is either time for a good cleaning or to purchase a new one.
Mopping is inefficient for large scale hard floor cleaning. Walk-behind and ride-on scrubbers are a more effective and economical way to keep hard floor surfaces clean.
While mopping does carry some dirt with it, a floor scrubber recovers the dirt as it cleans, leaving your floor clean and dry. They dispenses the cleaning solution, scrub it into the floor, and then vacuum it all up. The dispensing (solution) tank and collection (recovery) tank keeps dirty water completely separate from clean water.