They find nit picky stuff, or say they find it, get pictures on their phones.
Imagine a supervisory person coming to you.
Super: "I come in this morning and found this." *holding phone over with pictures of tiny amounts of debris on a floor in a room* "Those are time stamped, too. You need to meet standards."
Me: Well, time stamped or not it doesn't explain how you found it. Do you have a witness aside from yourself?
Super: "No."
Me: So, maybe you put it there?
Super: "Why would I do that?"
Me: Got me, maybe because you're insecure? How can I trust you didn't put it there? I cannot. Not saying you did, or didn't but there is likelihood you could have.
I know my work. Yes, I may miss tiny bits of what we commonly refer to as 'fly away' stuff. What the pictures show exceeds that. I don't miss that much. I leave places reasonably clean.
Other custodians, ten to thirty years in doing the work have checked me. They know my work is good, too. Yes, they offer constructive criticism at times. I take it, maybe do things a bit different next time, see if it helps, if not I go back to my way.
There is no wrong way to do the work, just do it. And, I do, do it. Maybe that's the problem, though? Hell, I don't know.
I have had only one teacher bring something up to me. That was addressed immediately by me and corrected. None of the other teachers have said word one to me regarding my work. The head principal assured me last week he had heard of no complaints.
Funny, I'm getting them this past week, from the assistant principal. So what happened from one week to the next? Nothing that I'm aware of, been doing the same work, same way. Hm, maybe because I compared the work to Sisyphus with another custodian? Roll a boulder up a hill, next day the same boulder is at the bottom of the hill again.
Like I said, don't know, don't really care. Even that discussion should not warrant a 'white glove' treatment, possible gaslighting. If someone thinks it does, that's retaliation and affirms the schools are running a closed shop, hostile and toxic.