Personally, I'd rather that the airliners modify the throttles. A disconnect microswitch would allow the the autopilot to take control of the engine settings. The handle and tubes that make up the throttles would disconnect. The tubes would be GUN BARRELS and the pilot would turn and blow the hijackers face off!
Roll a bunch of these cowboys off flights on a covered gurney and hold a press conference where the results of the attempt could be shown off. Pretty soon there will be nobody entering cockpits or attempting hijacking.