I think it's like an antibacterial dip/bath - it comes in a crystallised form that you dissolve with distilled water to make a solution that you then dip the fish (or, bird feet, in this case) in. I would think that surely there must be some equivalent of it here, but neither of the places I asked at could help me at all - they'd never heard of the product and couldn't offer me an alternative product...and these were places that specialise in fish. I have no idea why something that so many people have been talking about as a reliable treatment in America seems to be unheard of in Australia. :/ One of our chickens is the first for a vet treatment though, we have to do it in stages and she was the worst - she actually has a scab formed, so when I take her in tomorrow, I'll talk to the vet about what we can do for Whistles while he waits for his appointment.
You know you might be able to find something like that in the human foot care section of your local pharmacy.