Re:

My gut reaction, is -- no way. I wouldn't inject HCl into anyone, for fear of upsetting the pH of the blood.

But who knows.

Maybe tiny amounts of sudden acidity make the body respond, per this excerpt below, and the body responds with increased oxygen and white cells, which then just naturally kill off bad guys. Of course such a simple treatment, costing about 12 cents in material, would not be expected to be well-received by an industry which butters its buns from selling $ 2-a-pop friable tablets and capsules.

"Dr. Ferguson reported that very soon after an infusion of hydrochloric acid, there would be a marked increase in white cell count and in phagocytes; also that red cells had an increase in oxygen content. He suggested that one infusion of hydrochloric acid would increase oxygen in red cells in excess over what would result from maintaining the patient in an oxygen tent." Tweet