Very interesting thread, Anon. As a tulpamancer I find the relationship between one's imagination and hypnotic states mildly fascinating, although I never pursued that path of study myself. The first thought I had was to record the deactivation phrase and time it so that it would play after a particularly long hypnotic foray, especially one that required intense concentration. I could also see it being useful for a trip sitter of sorts when others enter trance-like states and require lucidity after a certain period of time had elapsed.
Have you ever attempted to use this phrase on someone you thought was hypnotised? I think it would be amusing if such techniques were used on sleeper agents or coded assets, provided they are just as susceptible.