Puzzled by cleaning

[GreatGooglyMoogly]

Okay, so we all know that washing our hands with water alone does not get them clean/ free of germs, and watching shows like How Clean is Your House shows you all of the dangerous bacteria that breed if you don't clean your house, so, how is it that microfibre cloths and mops are supposed to clean your house with just water?

They get the dirt off more easily than other cloths because of their texture but the germs are still there if you don't use any detergents