Doonesbury by Garry Trudeau for August 21, 1982
Roland: Ouch! How am I ever going to get all these damn bar tabs past accounting? Man: May I suggest the hotel commodore "laundry service," sir? Roland: The what? Man: You simply take out your bar checks and give everything else back to us...we re-do your whole bill, laundering out the bar bill by adding a little extra to all the other items. Roland: No kidding? You can bury a $1700 bar bill? Man: For a small consideration. Also laundered, of course.