Anhydrous ammonia is mentioned in Bruce Hoadley's book. It is apparently the
best method of bending wood (similar to steam bending).
He points out thought it is best used in an industrial setting, since it can
take days to plasticize the wood, requires special ventilation, is really
toxic, and I would not be surprised if, after a mistake, considering the need
for industrial equipment, the NYS DEC and the EPA will be all over you like a
pack of wolves (and they would probably be right).
Even assuming the stuff gets used safely, whcih is a really big BUT, how do you
then dispose of it? Put it into a local sewer, if you actually survive it, you
will probably be prosecuted.