I`m afraid it`s a case of;
1) stripping it all down and cleaning every internal section (not really viable unless you`re experienced in MV tech)
2) Time, in which case it will fade but could take a year +
3) Chemical warfare against the Polycyclic Aromatic Hydrocarbons present in there, Halogen (chlorine, Bromine etc...) gas will break them down, but will also corrode the metal(s).
and if as you say, had to put a Fire out in there, I think I would throw it away and get a new one (after I stripped all the good bits out).
PCAH`s are Born of Fire, Ergo: they don`t break down that easily :(
EDIT: IF you did want to go the Halogen route, the HCl + Chlorox bleach in a cup will liberate Chlorine, you can use Na-DCCA or plain DCCA as well, but you will need the HCl (hydrochloric acid) cement cleaner AKA Muriatic acid.
So long and Thanks for all the Fish ;)