Oh yeah I worked in fast food back in the day, long time ago actually. We had a cereal s*** smearer. Randomly once a week usually, sometimes twice, sometimes not for a week, The women's bathroom would get hit. Up the walls on the porcelain on the handles and the cracks and crevices and the grout and the floor on the mirror. The bathroom doors locked. Half the times when it happened a customer would come out and tell us, half the time it was one of the employees who would find it. This went on for what seemed like years but I suspect it was probably just a matter of a couple of months.
We were all good sports about it different employees who could handle the horror would help clean it. The managers did it as often as they could we just spread around the pain.
One fateful day, The dining room was busy but not too busy One of the employees went on break, the bathroom was locked. Well it was just about the right time frame post lunch, where everyone cleared out almost at the same time. The employee's entire lunch break went by and The bathroom remained locked.
We called the manager over she sat in that side of the dining room trying to figure out whether she was going to knock on the door and ask if the person needed help or just unlock the door and go in and do a wellness check.
All of a sudden one of our very long time customers emerged from the bathroom. We affectionately referred to her as crazy cat lady. She stunk of ammonia so badly that you could clean the windows in the dining room without any Windex. She was always nice and polite but you just couldn't sit within 10 ft of her.
When she walked out she saw two employees and a manager kind of staring that way got extremely flustered and started to say that bathroom was horrible. But we knew she had been in there for over 30 minutes. She was banned and we never saw her again.