The exercise involves putting a chopstick in between your teeth and attempting to play the flute. It takes a couple of minutes to redevelop a sound, but for some players, it is the answer to their embouchure issues. The destruction of the natural or formed opening by the offending piece of wood allows, and demands rethinking of how we form our embouchures.
The chopstick holds your teeth apart. The corners of your embouchure must be reformed in front of the chopstick. All focusing of the airstream done in the throat and mouth is undone by the disruption. The airstream must be refocused in front of the chopstick, which is less than 1/2 inch.
The end result is that the quantity of airstream necessary to form an acceptable tone is greater. Solid corners are formed to focus this airstream. These are all good things, especially for those individual flutists who have unfocused sounds. However it also helps those with closed throats and teeth by forcing them to use more unimpended air to produce an acceptable tone.
This exercise can be applied to any piece, but works best with more lyric music. Articulation is possible, but because of the interference of the stick, seems to be ineffective as a remedy for problems. My suggestion is that flutists give this a try, but not to do it more than 3 to 5 minutes per day.
The chopstick exercise is certainly is not an end all! If you find me performing with a chopstick in my mouth, please call a paramedic. I will need to be observed!
Please email me if you have any questions regarding this exercise.