I was watching Season 8 of Alone.  For those who aren't familiar with Alone it's a survival show.  Ten participants are allowed to choose ten survival items.  Then they're dumped in a very remote, wild location alone.  The last person standing gets half a million dollars. 
    They did an interview with one woman who tapped out. She described some techniques that allowed her to last as long as she did.  Her hunting and fishing weren't successful so she was eating just plants and she had no source of salt at all.  Her solution?  Eating her own mucus.  Snot and boogies.  Of course this is disgusting and the only reason I'm mentioning it here is because, gross and sickening as it is, it's actually a great tip.  If your stuck in a survival situation with no source of salt whatsoever this tactic will at least slow your body's loss of salt down.  But yuck. 
     Another tip which I've mentioned before;  if you are fortunate enough to get any fish or animals be sure to eat their eyes.  This is a very good source of salt.  Then maybe you won't have to eat your boogies.

Apparently eating bogies also boosts your immune system.

One man's disgust, is another man's panacea