I think the key is to ease others away from the problem topic, without using threats. Warning about the potential issues that might result (e.g. people might be offended, a flame war can result) is better than mentioning flags or other moderation measures.
@bwDraco Change the subject, gently but firmly. Ask them how $LOCAL_SPORTS_TEAM$ is doing, and tell them how they're much better than $OTHER_SPORTS_TEAM$
So... let's change the subject. Despite stalled renovations, I may be able to start putting together Astaroth by next week, just in time for Assassin's Creed Origins.