One of our big dogs recommended this when I worked with him last year, and I adopted it immediately. So have my partners. An easy "tweet tweet."
Guess what -- huddles start breaking when they hear the whistle much more effectively than when we come in simply saying, "First horn."
Book mechanic or not, it's worked really well for us, and our association's training program included this -- no surprise, since the big dog was teaching at the time.
