You can stabilize your wood by injecting a wood hardener or resin into the rotting piece of wood. This will cause the soft and rotting wood piece to harden.
When the chamber is closed, the air extraction will begin to take place. All of the air from the wood blanks will be extracted and taken out. Leave the wood in the vacuum chamber for a while.
Wrap your wood pieces in aluminum foil, Preheat your oven to about 160 degrees Fahrenheit and bake the wood. Leave the foiled wooden blanks in the oven for at least an hour or more.