Actually, I would suggest baking it for 2-3 hours, although you must be present and keep an eye on it the entire time. Definitely don't cook it any higher than 250 degrees, as that will increase the chances of it catching fire!
If that doesn't work, you can try soaking the wood in a solution of 1/2 cup bleach to a gallon of water for 24 hrs. Take it out, rinse it thoroughly, and then soak it for another 24 hrs - this time in JUST water, no bleach. I'd suggest to do this at LEAST twice to help it leach out any leftover bleach. Then hang it from something to prevent anything getting back into it and let it dry completely over several days.
Hope one of these works for you!!