Ooof this is one that I struggle it. Usually in my stories, I avoid slurs unless I really, really want the reader to hate someone and this is because I tend to react very knee-jerky and negatively to slurs myself.
In my story, the lead is a Mafia Queen and is very vicious, cruel, and ruthless. Since she is at the top of the criminal underground, she has a lot of unsavory rivals mafia families and business wanting her family to go down. She is a WOC so I do tend to have that levied against her at times, but I can never bring myself to use slurs even though I know it would fit because I really intensely dislike them (being Puerto Rican and have a black father does also fit into my negativity).
I suppose it's not really necessary in a work of fiction, but I do admit, if I wanted to make a more 'historically accurate' story, I may need to buck up and dig into that unsavory business. For now, it's not a bridge I want to cross.