I think I can be talked into drawing the line at sulfuric acid
I honestly don't see why the reluctance. You shouldn't ingest it at concentrations that cause physical damage, but the same applies to acetic acid, citric acid, and all the other acids humans frequently consume. Unless you're really sensitive to sulfur, it seems pretty much as safe as vinegar at the same concentration. "Salt & Sulfuric acid chips" might be tasty.
Mary's already taking sulfuric acid daily, and finding benefits rather than problems, so you can say that its safety is proven. I wouldn't take battery acid long-term, since I'm not sure of what contaminant levels are acceptable for batteries, but for a short term test, a drop of battery acid in several glasses of water (not sure how dilute Cellfood is) is probably less risky for contaminants than many foods in the supermarket.
I'm not trying to force anyone to take sulfuric acid. I'm just pointing out that the fear about it seems irrational, probably due to confusing common applications for high-molarity sulfuric acid vs other acids that are commonly thought of only in low-molarity concentrations (acids normally in foods). High-molarity HCl is used in drain cleaners and brick cleaners (with appropriately scary warning labels), but people take it--at appropriately lower molarity--as a health supplement.