Hello and welcome to Just Answer. I am a licensed veterinarian and would be happy to answer your questions.
It sounds like you may be describing what is called granulation tissue. This is what happens when things heal from the "inside out". In his case, if the burned tissue is sloughing off, the tissue underneath is filling in and trying to replace it. It can look kind of raw, but it may be normal.
Let me ask you a few questions. Is there any drainage from the tissue? if so, is there an odor? Does it still bleed?
Is the pad or involved tissue swollen? Is he limping? Is the raw tissue underneath a nice pink color?
My biggest concern is infection. The underlying tissue is very at risk for infection as it tries to heal. Even if it is healthy, it can have a slight odor, but it should not drain or smell like an abscess.
You could try to soak the foot in either room temperature saline or epsom salt water once or twice a day. This will help to keep clean the foot. If applying ointment makes him lick more, I would not use that. If it doesn't seem to be getting better in a few days, I would have a vet evaluate it. It would be best to keep him indoors until it is fully healed.
I hope that helps. Please let me know if you have any further questions.