As a potter...I've been making " paper clay", which is a slurry of soaked paper ( toilet paper) added to clay slip, then dried out to be workable. This is not unlike the example of clay coated fibrous leaves encasing food to be baked in woodfire. The cellulose fibers make miniature channels after the clay is low fired & can even be used to make water filtering vessels.
So, maybe like biochar, it is a place where mycorrhizal fungi can establish a home?
