It says that if you use baking soda and horticultural oil it will change the pH on the leaf so the bugs won't survive. My question is, what pH would that be? I have a machine that can make different pH water and I can spray that if I know the number on the pH.
There is several sources of research written on the benefits and uses of this natural disease management method, though I have not been able to find any material that lists what the ph would be of such mixture.
Here are a few more links you may find interesting.