I used the phrase twice to two separate aircraft leaving CAS because there is adjacent CAS where infringements are common. On both occasions the pilot subsequently infringed CAS within ONE MINUTE, one into an airway the other into another units CAS. Pretty much renders the phrase pointless?
Sad thing is and what most atco's have learned is that when something like this happens they will get blamed for these incursions if they haven't said the phrase, So the phrase has become a cover your ass thing.