I actually got a job as the assistant manager at a movie theater a month before The Phantom Menace opened and I had to quit beforehand because I couldn't see in the pitch dark driving home.
Theater was closed for renovations and the manager pulled me aside after I cleaned the popcorn machines and said, "Holy crap what did you clean them with?" And I said, "A new toothbrush. They were filthy."
That was probably the last time they were clean.