Cordwood insulation

I will be building a cordwood house in NW Washington in the next couple years, so I'm starting the process of gathering boatloads of materials for it. Most publications and discussions list sawdust as the insulation choice, occasionally spray foam. Sourcing enough sawdust might be tricky for me... But what about microshredding waste paper? If I apply the same pest/mold treatments as sawdust gets, wouldn't it be awful similar? I could also mix in some of the finersoftwood sawdust I get from my miter saw. Has anyone else used paper they processed themselves for insulation?

Also, this is kind of off the wall, but the previous owners of the land were kind enough to leave about a dozen old tires in the forest. Since rubber is used as an insulator, would there be any harm in chopping them up into pieces and sprinkling some in the insulation cavities? It would be nice not to pay to dispose of someone else's trash, and might put them to good use...