According to the Cystic Fibrosis Foundation, salt attracts water into the airways, which thins the mucus, making it easier to cough out. Research has shown that inhaling hypertonic saline twice a day helps people with cystic fibrosis experience fewer lung infections.
Alternatively you can mix 1/2 teaspoon salt in 8oz hot water, stir it and drink it throughout the day.
Note: The RDA for sodium for an average adult is 1,300 mg with a tolerable upper limit (UL) intake per day of 2,300 mg. Sodium chloride (table salt) is approximately 40% sodium. One teaspoon of table salt = 2,300 mg sodium. Do not exceed one teaspoon of table salt over the course of a day.