My dad tells a similar story of an offshore oilrig person giving a tour to some C-Suite type people. His alarm goes off, and he pauses the tour to throw an oily rag on the floor. 5 minutes later the rig supervisor person steps out of their office, looks around, shouts about oily rags and health&safety risks, then goes back into their office.
With a similar "punchline" about giving the supervisor something obvious to complain about

So, perhaps call it an "oily rag"?