Salt helps heal cold sores by acting as an antiseptic and drying out the sores, according to New Health Guide. Both sea salt and table salt can be used on cold sores to achieve this effect.
New Health Guide advises applying the salt directly to cold sores. Wet a cotton swab or soft cloth with hot water. Place a small amount of salt on the cotton swab and apply it to the cold sore. The salt and hot water work together to reduce inflammation, get rid of bacteria and dry out the sore.
Med Health recommends using a combination of salt and toothpaste on cold sores. Mix a small amount of salt with toothpaste, and apply it directly to the cold sore. Leave the toothpaste on the cold sore overnight. The salt and toothpaste mixture dries out the cold sore and any puss that is present. Salt and toothpaste mixtures also work as a barrier and help prevent dirt and bacteria from getting in the sore.
While salt is fine to apply directly to a cold sore, SFGate recommends avoiding salty foods such as chips, pretzels and pickles when a cold sore occurs. Salty foods can irritate cold sores and prolong the healing process.