Just to add to it...
Adding/checking an entry at start-up should be done via queueInitializers.properties. To the best of my knowledge that hasn't been made into an "official" xconf file. Which means if that is what they have done it's not officially supported.
Adding an entry to queueInitializers.properties and providing code to executed in relation to the entry is the "official" and proper way to add/check entries at run-up.