Mg doesn't help much. Haven't tried bicarb. Have you found these useful?
Likewise, sodium bicarbonate antagonizes acidity and can be used transdermally in foot and hand soaks. I even took bicarb baths during high ammonia/uric acid causing salicylate intolerance (urine pH went from 4.5 to 6 and food intolerance is gone) and have been using it as a shower scrub and am very happy with it.
@ariel I am appalled by the inflammation psyllium and potato starch caused me I am still trying to find a way to take RS and/or fibers and trying to figure out what gives!