File:Breakout device used by Oliver Wayne Coursey to escape from Maricopa County Jail in May 1949.png

English: String, Wax, and Dentifrice: It all started in May 1949. Oliver Wayne Coursey, 31, charged with attempted robbery and kidnaping with intent to rob, was then placed in tank A on the sixth floor of the Maricopa County Jail, Phoenix, Ariz.

Coursey had made a previous attempt to escape from his cell, but had failed. He decided, consequently, if he could not walk out, he would cut his way out. Mustering all the ingenuity at his command, Coursey removed the strings from his mattress. Scraping wax from the milk carton and impregnating it into the string, he was ready to attack the bars of his cell. His abrasive elements consisted of a high-grade dentifrice mixed with plaster scraped from the outside of the building and small portions of kitchen cleanser. Short pieces of pencil tied to either end of the string made adequate handles for a job which would take time and patience. Coursey had plenty of both. He cut each bar from the outside in with his improvised saw. The effect was barely discernible and smooth as glass, bearing none of the earmarks of a cut made with a hacksaw blade or a similar tool.

Pieces of bubble gum were placed in each bar in an effort to conceal the cut from the jailer.