It sounds like at least unorthodox if not inappropriate use of a flirt pole. They are meant to encourage prey drive. I did use a longe whip to call Barker Sisters the First to the house. They thought the snap meant something good was going to happen, it didn't instill fear.
If you are relying on the noise to = "right now this minute" you could likely use something smaller that made a very similar noise (cap devise?, clapping two boards together) Another option would be to begin pairing the snap of the whip to another cue and phasing out the whip.