I have considered making people drink poisons like charybdon, however, that would only be effective against Knights. Instead, I force them to sip choleric or something else. More or less, it forces at least one sluggish command which can be moderately useful in catching someone up in aeon. Furthermore, if I have control with a pooka, I might as well use it.

However, given every Ur'guard (except Thorgal when he was Ur'guard) whores charybdon, it might be worth forcing them to sip it.