I've dealt with a number of wounds from various causes. I used to apply liberal amounts of hydrogen peroxide first, or Betadine first. These days, I've had much better results with salt water. I make it strong enough to taste like the ocean (best way I can describe it), then I soak, douse, or drench every few hours depending on how the patient (chicken, dog, cat, etc) is doing.
I also put the patient inside a quiet, dark, climate controlled room in a large cat crate lined with potty pads (dog supply section), a bowl of nutrient/vitamin C water, and a little wet food. I have found that if they drink and then eat within 24 hours, they're probably gonna make it. But that salt water has been a real miracle--bacteria don't do well in salt solutions.
Bless your ducky! May he make a speedy recovery.