I guess I should have taken photos, but I didn't think of it until later, and anyway it was rather gross... So, one of my hens had Bumblefoot - definitely, and a pretty bad case. I tried to drain the swelling by holding the afflicted foot in warm water, peeling off the scab and gently squeezing out the pus, but it worked only partially and after two days it was swollen again. So I tried applying an antibiotic ointment which I just happened to have on hand - a combo of Chloramphenicol and Prednisolone. I did it twice a day for two weeks and it worked like magic! I never had to squeeze, cut or drain anything again. The hen is now broody and her feet look just fine. Just thought I'd share!