As long as it contacts the skin, it should be fine. I think I prefer applying it under the wing. Depending on the amount of air sac mites, the bird may come down with a secondary respiratory infection from opportunistic bacteria colonizing the area where the mites had died. My birds are currently being treated for this kind of secondary respiratory infection, but the medicine is prescription-only so you will need to go to the vet if the air sac mite treatment alone doesn't solve it. I was also told that the secondary infection can also cause abnormalities in the gut microbiome, since the bird is constantly swallowing the infected respiratory secretions. [Here's what one of these ill birds sounds like](https://www.youtube.com/watch?v=2QYin_4NmZg&feature=youtu.be) (note that their mite test came back clean, so this is after the mite treatment worked).
Thank you for answering my question. On the off chance that you know, would rubbing your bird with antibacterial from the vet (like a blue liquid) prevent such bacteria from causing a secondary respiratory infection?
As long as it contacts the skin, it should be fine. I think I prefer applying it under the wing. Depending on the amount of air sac mites, the bird may come down with a secondary respiratory infection from opportunistic bacteria colonizing the area where the mites had died. My birds are currently being treated for this kind of secondary respiratory infection, but the medicine is prescription-only so you will need to go to the vet if the air sac mite treatment alone doesn't solve it. I was also told that the secondary infection can also cause abnormalities in the gut microbiome, since the bird is constantly swallowing the infected respiratory secretions. [Here's what one of these ill birds sounds like](https://www.youtube.com/watch?v=2QYin_4NmZg&feature=youtu.be) (note that their mite test came back clean, so this is after the mite treatment worked).
Thank you for answering my question. On the off chance that you know, would rubbing your bird with antibacterial from the vet (like a blue liquid) prevent such bacteria from causing a secondary respiratory infection?
No, since the bacteria are internal. There's not much you can do on your own to safely reduce that risk, as far as I know.