Check this out: I saved this link awhile back and lots of people swore by this as a non-surgical cure. I've not treated bumblefoot before, so am just passing along info
https://www.backyardchickens.com/forum/viewtopic.php?id=303829&p=1
Good luck!
Andrea

https://www.backyardchickens.com/forum/viewtopic.php?id=303829&p=1
Good luck!
Andrea