I tend not to use Friends because NPCs can turn hostile, but I’d understood that if you vacate the area before they do then they’ll have forgotten if they don’t see you again for long enough? It’s not something I’ve verified myself though.

For anyone who hasn’t seen it already, there’s been some other recent discussion of the spell here: https://forums.larian.com/ubbthreads.php?ubb=showflat&Number=845373

"You may call it 'nonsense' if you like, but I've heard nonsense, compared with which that would be as sensible as a dictionary!"