Summary: lumber can be fumigated successfully with a volatile pesticide.  

Case 1:  Most of the ash trees were killed here two years ago.  The dead trees quickly became infested with powder post beetles and other borers. I wanted to saw one large tree to produce some "wormy ash " lumber.  It is said that to kill the boring larva the lumber must be heated.  

I wet all the surfaces of this lumber with malathion, a somewhat volatile insecticide (it smells hence it has some volatility).  The lumber was then dead packed and wrapped in plastic.  The idea was that the critters within have to breathe and they would be breathing malathion vapor.  Two days later I unwrapped and there were hundreds of dead grubs on the plastic.  Apparently the treatment caused them to crawl out before they died. 

The lumber was given a borate treatment for long term storage and put up on sticks.  It has been two years and there remains no evidence of fresh boring (no sawdust piles). Success!

Case 2  I recently cut a dying ash that somehow escaped the first wave of emerald ash borer.  Initially it did not have signs of infestation but they showed up soon after as dozens of holes with saw dust coming out.  I assumed the infestation was recent and the critters had not bored deep.  I soaked the lumber on all sides with Imidan, a poison related to malathion commonly used for fruit trees. (I didn't have Malathion on hand).  Sawdust was brushed away so that new boring would be apparent.  There was none.  Success!