If we can make "Tide Pods", small packets of thin plastic that contain but also SEPARATE two or three different liquids until the membrane is broken, we should be able to make FIRE PODS as well.
When a tire fire happens, we fly over the fire with a cargo plane loaded with fire pods and BOMB the fire. The pods break or melt open and the chemicals inside instantly mix and make train loads of fire extinguishing foam. The pods could contain baking soda and vinegar, and the foam would be all natural.
Remember the volcanoes we built in grammar school science class? Only TWO teaspoons of baking soda and an ounce of vinegar was all that was required to make our volcanoes erupt. Imagine how much OOZE you would get from a cargo plane (or two, or three) loaded with those two inert substances.
Baking soda and vinegar is CHEAP. After the tire fire is put, no "repairs" are needed. Just pile more tires on top of the ones that burned.