Conundrum

Related.
Suppose you know someone who engages in boorish behavior; what kind of feedback can you give such a person, that'd be most likely to help them to recognize it, to see how others perceive it, and to stop it?
Particularly if they're wired to interpret criticism as insult.

Constructive answers only, with sample dialogue, please.
(if you make any other comments, save a copy, because it may get deleted.)

Bonus Q: how, as a society, can we most constructively integrate people who are "high dudgeon" addicts?