Be sure to clean it out completely. Maggots are nasty and there are lots of flies out there right now that might have laid eggs in the wound.
I only have Orcheln's available to me for right now. I have some amoxicillin, can chickens have that? I was able to break down the dosage for kittens and dogs. I don't have Oxine, I will call Orcheln's, but I do remember a wash thing that the vet gave me for some kittens. I will look and see what that is too.