http://www.vivehypnosis.de/?p=5181
Whenever you wear this trigger, you will feel as if a stiff rubber ring has been surgically implanted in your lips, making it almost impossible to close your mouth. You will barely be able to close it for a few seconds, having to work hard against the rubber ring, before they will return to an O shape.
You need a length of string or a bracelet for this file which will become your trigger, and you need to wear it while you listen to it.