I am asking for help with my father’s treatment (prayers, advice, financial assistance).

The fact that baking soda cannot be "natural" or "chemical" is another argument against charlatanism. Both are Na₂CO₃. The fact that "natural" soda costs many times more is just another way to make a profit. Scammers take advantage of confusion and the inability to think completely rationally. Indulging them only multiplies human suffering.