I would definitely be watching for signs of infection and put him on an oral antibiotic if needed.
As Ryle said, a lot of the ointments people recommend actually slow healing. Your best bet with something like this is rinsing with plain water to flush out dirt and bacteria once or twice a day, keeping it bandaged and him stalled. As far as for what to put on it? A bacteria-static hydra-gel would be your best bet. It would prevent bacteria growth under the wrap and keep the gauze from sticking. If there are signs of infection, then I would begin treating with an antibiotic. Right now it is so fresh I would be wary about putting anything paste like on it.
When it starts to granulate, keep wrapping and rinsing. When skin starts to grow over, keep wrapping and rinsing. When there is skin entirely covering it I would begin applying a thick, lanolin based ointment to keep the skin moist and start weaning him off the wrap and start hand walking to prep him for "outside".
If he is really going to be an idiot for the first weeks of stalling and Ryle's suggestions are not working, don't be afraid to use a mild sedative to calm him down.