Whew! I didn't think of autocorrect!
It's hard to say. Black tissue is usally dead tissue but it could also be scabs. Well, yes, the black will go away, but what you won't know for a while is whether he loses some height on the tips.
I'd probably put Neosporin on whatever is already black. Vaseline is supposed to prevent the frostbite. The ventilation is the most important thing, to allow this to heal and prevent more damage, as well as to vent the ammonia.