I not going to be an a%* and tell them how to act.
If they're not displaying proper jumpseat etiquette, then it's not "being an ass" to teach them. You'll be doing them a favor, because they're bound to run into somebody else, probably at a mainline carrier, that's going to go off on them and possibly boot them off the airplane if they don't act appropriately. Politely let them know what the proper jumpseat etiquette is. You're not doing anyone any favors by letting them wallow in their ignorance.