Have you soaked her in a tub to get it clean as possible and then felt it to see if it’s hard or soft / fluid filled?
I think topically you can spray it with vetrycin and apply antibiotic ointment (no pain relief added) in between tub soaks
Or bucket soaks with Epsom salt added to the lukewarm...
Gale has warned me to stay home and be on fallen branch duty. I think the ducks have a private hotline to Gale. They are deathly terrified of anything that falls or blows around in their yard.
That’s wonderful news. Have you ever thought about making a sling instead of using all those towels?
Thread 'How to properly splint a duck leg?'
https://www.backyardchickens.com/threads/how-to-properly-splint-a-duck-leg.1531446/
I might try wrapping it in Vet wrap like making a soft cast?
Or you can use a wheelchair or a sling like these
https://www.backyardchickens.com/threads/question-about-splinting-ducks-leg-how-will-she-sleep-and-sit.633233/
Oh my goodness, aren’t they so adorable!!? I have no idea because I don’t have Muscovy’s but there are people who have them here. Someone will probably come along soon with a good answer. Maybe @Miss Lydia ?