Did you try something like polyclar to drop the carbon? I havent bothered with carbon at all, a few weeks aging on a bunch of toasted white oak seems to mellow things out to me, and adds tons of smooth flavor as well. Some might say its over oaked but I enjoy it that way.
I did manage to scorch an AG batch a while back, I believe it was because I used a beer yeast which left some sugars behind, also I wasn't patient enough to let the it clear on its own, then to top it off I wasn't careful enough when racking to the boiler which all added up to a cloudy mess and a strong burnt flavor that will likely never age out. Its been on a bunch of charred oak for several months now, if that doesn't clean it up I'll try carbon filtering. If that doesn't do it I guess the toilet can have it.
I'm on to LME now, fermented with premier blanc and then polyclar.