Soap
A woman was unhappy with the way her laundry was done at the local Chinese Laundry, so she wrote a note and put it in the bag with the next collection of soiled clothes: "USE MORE SOAP ON PANTIES!"
She got the clean laundry back, and was still dissatisfied with the results, so the following week she enclosed another note: "USE MORE SOAP ON PANTIES!"
The Chinese laundryman became very annoyed, and when her clean laundry was delivered, it contained a note from HIM: "I USE PLENTY SOAP ON PANTIES!!! USE MORE PAPER ON ASS!!"