Get the dust IN THERE on the skin. Pay special attention to vent area. I part the feathers and inspect the entire bird--my assistant (son) holds the bird for me. He tilts the birds so I can look under their wings and their bellies. REALLY get that dust in there good. Your birds will be dusty for a few days after as this stuff clings really well to their feathers.I plan on doing the birds outside in the open, does the dust need to make skin contact? Or should I just coat an entire bird and let it settle in naturally? Lol, I'll need to find a bottle now, interesting idea.