Burning paper in bulk for destruction in an uncontrolled process doesn't really work, you end up with huge chunks of unburnt paper because it couldn't get enough oxygen, plus the ashes may be recoverable unless mixed. Especially bad if you only get it halfway done because an angry mob shows up and stops you.

For fast emergency destruction of documents, the NSA has developed a procedure https://media.defense.gov/2021/Jul/02/2002755769/-1/-1/0/EME... where paper and oxidizer get layered in a burn barrel. "The ratio which was adopted was 65 pounds of paper for 100 pounds of nitrate" gives you an idea how much extra oxygen is required for proper combustion.