When my grandpa worked as a custodian at one of the schools, while I was there to visit, I got to go to work with him one day. He showed me how the floor polisher worked, and he cleaned some of the hall, and a staircase while I watched. You soak it, the machine scrubs it, then you suck the water up. It's kind of cool. I got a lot of my really cool pens and mechanical pencils from grandpa.