well this is interesting approach
so instead of filtering out notes containing word, you would filter out any relay that relay the word. ie that would mean, when you see single note containing banned word, you would instantly ban whole relay.

nostr:note1yywtc4rzqgnfyzgmyywcfk2av0fgahmj243wh80f4wlrefnm92csgpgr4k

i dont really care what people do with their ban filters, but being this sensitive with word filters may not be what you want. you find out yourself banning thousands of relays by mistakenly putting too common word in your filter list.