Horseshit. Snopes: Duck Echo Wikipedia: Ducks Quack echo myth Myth Busted: A Duck's Quack Doesn't Echo Mythbusters: Does a ducks quack echo
No, but he did invoke the line at times in humor. And in 1938 in Only Angels Have Wings, he's says "Judy! Judy!"
Never say "never" my friend. I know I have heard him say it watching OU games years ago. https://sports.yahoo.com/ncaa/footb...Jackson-mystified-by-longevi?urn=ncaaf-wp3691
"Peter Bogdanovich believes that the genesis of the imitation came from Grant's delivery in several lines in Only Angels Have Wings.. 'In the film his former girl friend is called Judith or Judy (played by Rita Hayworth). Cary has lines like "Hello, Judy. Come on, Judy. Now, Judy." But he never said "Judy, Judy, Judy." ' Judy Quine has another explanation: 'Cary told me back in 1955 that when he did the Lux Radio Theater, they used his voice introduction for Judy Garland, who was a guest for the following week. He recalled some banter where he could have said "Judy, Judy, Judy," but he wasn't sure.'