[Christ]

What chemical will neutralize and/or remove sulfate build up?

That would be the key - neutralize and remove the sulfates from the lead grids (or between plates, depending on the type of battery in consideration), and stop the shorting.

If you "dump" a battery, the contents in your container will be sulfuric acid, water (maybe), and lead sludge.

Often, cleaning the lead sludge from a battery and adding new electrolyte and PURE demineralized (deionized) water is sufficient to "renew" a L/A battery, although not to original capacity. (Remember, you just removed some lead... it's not going to be 100% anymore).

Salts, red wines, and some other things (Coca-Cola, I think?) can temporarily "boost" or "quick-charge" a battery due to chemical reaction; However, most batteries you'll come across today are sealed or "maintenance free" type, and accessing the cells is difficult/impossible without damaging the casing.