I made a mixture of beeswax and coconut oil to apply to the dried kombucha leather. I eye-balled how much of each ingredient I needed and melted it in a pot and used the the liquid to apply on top of the kombucha leather before the liquid hardened. It added a greasy layer on top of the kombucha leather. I sprayed water on top of a piece of kombucha leather without the protective layer and then sprayed water on top of a piece of kombucha leather with the protective layer. The bare kombucha leather, once dry, reabsorbed the water and went back to its original form. The beeswax and coconut oil covered kombucha leather was water resistant not waterproof. The water would sit on top of the kombucha leather because water and oil don't mix but once I started rubbing the water into the kombucha leather, it reabsorbed like the control piece. It seems like any oil based coating would make the kombucha leather water resistant, not water proof.
Note: The white spots you see are clumps of the beeswax and coconut oil that I didn't rub all the way into the kombucha leather.