A middle school for girls was faced with a unique problem. A number of girls were beginning to use lipstick and would put it on in the bathroom. That was fine, but after they put on their lipstick they would press their lips to the mirrors leaving dozens of little lip prints.
Finally the principal decided that something had to be done. She called several of the girls to the bathroom and met them there with the custodian. She explained that all these lip prints were causing a major problem for the custodian who had to clean the mirrors every day.
To demonstrate how much work they were making for the custodian, she asked him to clean one of the mirrors while the girls watched. The custodian took a long-handled brush, dipped it into the nearest toilet, and proceeded to scrub the mirror.
From that day on, the problem of lip prints on the mirrors was completely eliminated.