DLawson
Member
What's a church key? Maybe it's a Protestant thing, unknown to we Australian Irish Catholics.
The way I heard it, Wild West Uncoothnicks would carry their beer openers (varies with the teller whether that was the bottle opener or the can opener) on a string around their necks. When going to a civilized town, sight of that evil tool was enough to bar their entry to churches where decent people would be -- figuratively locking the doors.
The real etymology is probably much less entertaining.