You've reminded me of something JohnW but it doesn't sound exactly like what my Grandad used to say. Something "to catch meddlers" but I don't think he said "layoers". I wish I could remember. It's just vaguely there in the back of my mind.
Never heard the one about the plank tho.
We should have a quiz to see if people can "translate" Lanky! Busman might have a bit of trouble.
