I have never heard of using it on their outsides, only as a
dietary supplement. Since it's harmless, I'm sure it
wouldn't hurt but I think it would be awfully messy and I
would be afraid that getting something that greasy/oily on
their feathers might lead to over preening, then to
plucking. Harmless or not, I'm betting they would worry
themselves to death, trying to get rid of it because
something like that, in the wild, would maybe hamper flying,
which would mean extreme vulnerability to predators. When
mine have dry skin/feather issues, I put aloe juice, straight
from the plant, in their bath water. I cut an arm from the
plant, slit it open, squeeze the gooey in and mix around.
Aloe is very good for them, both inside and out so it doesn't
matter how much you use. You might try that first. Oh, and
it's also good to massage a little into dry feet and legs and
it even works a bit as a beak conditioner.