I wrangled him up, brought him into the house (under protest) and settled him into the sink for a good cleaning. He seemed to like to cold water from the sprayer on this hot, hot day, but was significantly less happy about the vinegar I poured over his feathers and wounds. I got him cleaned up, some Bactine on his owies and set him up in a temporary "sick bay". OK, I know it's not fancy (it's pretty ugly) since it's all built from leftover parts of other projects. But it's sturdy and predator proof.
I took Buffy's old broody box and a large wire dog kennel pushed against the open gate to expand the outdoor area and got him set up in there so he could heal up without the others picking on him. He really started to freak out when the rest of the Muscovy lined up and headed into the barn for bedtime. So I grabbed one of the small Muscovy girls and put her in there with him. He calmed down immediately and she didn't seem to mind; plus she wasn't pecking at him. These birds are extremely social and are always touching each other so I knew it would be too hard on him to leave him all alone. Once it was full dark I saw that the two of them had gone inside to the nest portion of the broody box... that's a good sign. I guess in the morning I'll take her out when I treat his wounds again.
A guy on one of my homesteading forums uses honey on his ducks wounds and says they heal up really nice. My only problem is I can't wrap a bandage on him by myself. He's a big boy and I need both hands to hold him so I might have to call in reinforcements - who? I really, really dunno. Lordy, I need a second pair of hands... Bobby! Hey, little bro... I'll throw it out one more time, dude.
UPDATE: I kept this Muscovy boy in sickbay for 2 days and checked on his wound twice a day. I used a lot of neosporin on it and he seems to have recovered fine so I let him back out with the rest of the gang. This is great news!