Well, it's better left to the more chemistry-minded folks, but my take is, it is probably ok to extract.
I just recently extracted a good portion of rotten cactus, and ended up with the best quality of mescaline for myself to date. I did an STB, then salted out with sulfuric acid. I would think if you did a similar extraction with this bark, specifically salting with fumaric acid, you should end up with only the good stuff, and nothing toxic.
Are you able to separate anything without mold, or is it one big ball of mold?
Be an adult only when necessary.