It's what he said... started from his stand-up routine and carried over to the show. Kinda like Larry the Cable Guy's, "Git'R'Done". Like a trademark line, I think...I'll research it, and post what I find here.
So, dacableguy35 I won't hold you to your initial bid if authenticity is an issue for you. I just discovered proof that it is a pre-print as posted above.
tigers101, this is all I could find... it's from the Baltimore Sun... "RRR" is a sound familiar to fans of the Tim Allen show "Home Improvement" -- it's Allen's battle cry, the primal scream of a guy who loves his tools"