I tried adding lots of salt when I experimented with raw, zero-carb diets due to a concern about another quite different issue. The severe fatigue I invariably got after being 3 weeks on ZC diets was definitely not resolved by the consumption of this extra salt, let alone the other health-problems I got from that type of diet, so I went back to a raw, omnivorous palaeodiet, and things improved back to normal. Not suggesting that it might not work for others, it just didn't work for me.
Geoff