I have had success doing a search for a certain word and blocking all users who use it.

Is the magic word “airdrop” perchance?
I don't want to say the word because of a nam-shub situation. I would describe it as very much like #zxxpathon. blocked 1027 users so far. I'm sure your word is a good indicator too. #blockathon <- this word is fine with me though
You blocked z@pathon?
They're great fun. They also help test Lightning wallets capabilities for when zapping increases 10X
That is what I block. For me, those things are annoying and they jam an otherwise creative and occasionally meaningful signal. However, I wouldn't ask a relayer to block them because they are good for me testing my own content curation tool. ...and because centralized relay based censorship just ain't right.
Are you blocking the people who do it? Most of the best nostriches do z@pathon so you’re blocking some great people. Or are you blocking the notes that contain them?
Until I get ML working, I have no choice but block the users. (I'm not far off though https://www.youtube.com/watch?v=tO0Mmp9T-6o)