Perhaps a few hours in a room with a disapproving doberman will prompt them to desire to shed their ignorance.
Offender: “I couldn’t take it any longer; the more I justified to the dog how I never trained Fifi, how I gave her treats for ‘looking adorable’, and how I even carried Fifi in my purse, the more the doberman glared at me contemptibly. Have you ever been glared at contemptibly by a doberman? It’s a most dehumanizing experience?”
(Hmmm...me thinks a disapproving doberman will be in contact with me shortly to express its disapproval of my proposal. ;) )