I agree. Wrap the whole foot. You can tear the tap into narrower strips, which might be easier to manage. If you wrap her in a towel, she will be a lot calmer and more still.
If you think there might still be mites in that toe, I would try neem oil mixed into an ointment base after that epsom salts bath recommended by Wyrop. Neem is highly toxic to mites, and is safe for your hen and her chicks. The ointment will help keep the skin moistened so it can heal. Try...