According to a radio report, a middle school in Oregon was faced with a unique problem. A number of girls were beginning to use lipstick and would put it on in the restroom. That was fine, but after they put on their lipstick, they would press their lips to the mirror leaving dozens of little lip prints.

Finally the principal decided that something had to be done. She called all of the girls to the restroom and met them there with the maintenance man.

She explained that all these lip prints were causing a major problem for the custodian who had to clean the mirrors every night. To demonstrate how difficult it was to clean the mirrors, she asked the maintenance guy to clean one of them. He took a long handled squeegee（橡胶清洁器）, dipped it into the toilet and then cleaned the mirror.

Since then, there have been no lip prints on the mirrors.