For an owner who knows he has such an amp, this would be worth doing.
Obtaining or making an amp sized heavy duty polythene bag that can be
resealed easily and some sachets of activated silica gel crystals and a
large jam/pickled gherkin jar to keep the oven acivated ones in, until use.
After each use of the amp , place amp while still warm prefereably ,in the
bag with a fresh sachet from the storage jar.