Don't do it, you'll feel dirty if your a true Patriot.
The only exception in which it’s accessible to fly the American flag upside down, as per the U.S. Flag Code, is to signal danger or distress. The U.S. Flag Code says that flying the American flag upside down signals dangers or distress. When flown upside down, the American flag is recognized as a signal of danger or distress. But reports of people using an upside-down American flag to get rescued are few and far between.
https://starspangledflags.com/why-you-shouldnt-fly-the-american-flag-upside-down/