@RememberUsAlways
I usually mute for 1-3 days, depending on how bad the behavior is (not in the absolute sense, but from the viewpoint of curating my experience), and I together with the mute I add a note for the account on the profile page. If a person accumulates a few mute notes, I mute them forever.
Worked so far, but I have no idea how would it work for crowded places.