It gets really hard to think of actual ârulesâ outside of correspondence, to be honest. 
I mean, without getting really out there with it, like, âwitches donât kidnap people and sacrifice them at altars, they do it in their basementsâ and âwitches donât eat people, they just turn them into pies and sell themâ because, of course, we donât. 
Uh, we donât⊠Right? Do we? 
(Or maybe my imagination is just terrible. Thatâs a pretty good possibility. )
Yeah, I donât think anyone is saying theyâre requirements. Just that if we do use them, we canât make up what their uses are and expect things to work. So, like, I will totally skip cinnamon in drinks, coriander (cilantro), and a few other things out of taste preference, but I look for something else with the same purpose, rather than picking something at random.
Speaking of, funnily enough, I skipped and changed ingredients in my own spell recently. I canât even stick to my own word. Harmony's Shield: A Freezer Spell for Conflict Resolution. But it worked out well, I think. 