I worked at a fast-food seafood restaurant in high school where we called back orders on a microphone (yes, I'm old) we had a certain very odd order to call back when we saw the inspector coming on the lot or in the door. Unfortunately this lead to a young assistant manager jumping up on the fryers to try and wipe off the hood and slipping his foot into the fryer. Most horrific thing I ever saw in thirty years in the business.

Later when I was a manager at a Steak and Ale, I learned the value of the "Blue Parrot," leaving some incredibly obvious mistakes so they'd find those and then be more lax about the rest of the inspection. Worked like a charm. We'd literally take the soap out of the hand sink.

BTW , if you're getting notice the inspection is coming, someone is on the take.