From my own reading, my understanding is that
by adding 1/4th teaspoon of salt per liter of
water, you improve the body's absorption of the
water. I keep a small jar of himalayan salt
crystals and suck on one like a mint and sip
water in between. I also keep a bottle of salted
water and take swigs of it during the day.
Getting in the salt is helping me, I feel. I sleep
more often through the night or awaken once.