I have sucessfully used fumigated equipment that came from hives with known
active AFB, so I submit that equipment can have active AFB spores fumigated.
 Maryland uses an ethylene dioxide chamber; there are other fumigation
methods also (although all of them require special equipment/precautions).
 
As far as getting rid of AFB once and for all, that sounds unlikely.  Unlike
mites that die when they kill a colony, the AFB spores have effectively an
infinite "shelf life".  As long as there is an old hollow tree, old hive body
in the barn attic, or anything similar, there is a source for AFB.
 
W. G. Miller
Gaithersburg, MD