Lol!
Like I said, just reapply. I applied it daily during fall, since they'd wipe it off in the dirt. If that's what's happening to your girls, you might need to apply daily / every other day.
I've put lots of Vaseline on my birds. They can't really get frostbite with it on (well, im sure they can,but it proved to prevent it at -60, and i dont think WV gets -60! :) ) Once it rubs off / gets absorbed, then apply more. It's ok if is dirty.