I would start with other exclusionary measures....have you tried bird spikes, shiny metallic strips, the noise box, or fake owls? Removing food source, standing water, etc? Cleaning is the most cost effective pest control. We had a falconer come out once, which was pretty awesome, but I think that was a last ditch attempt by a factory manager desperate for unprotected outdoor feed storage that shouldn't have been.
I've used an outdoor treatment for flying insects but never birds...it knocked down the population momentarily but the conditions that caused the initial attraction still drew in bugs droves...standing water / food stored outside.
Edited by magenta_majors, 05 December 2014 - 12:24 PM.