I've run across that several times. Managed to use it once myself. Quinol's commonly used by good players.
A friend was a ranked Scrabble player for a few years - rarely plays a game where she gets less than 500 pts and is usually in the 550 - 600 range. My target is to stay within 200 pts of her. She throws down words that make me shake my head. 25 minute games and she's throwing down 500+ points.