Putting salt on a cold sore can sometimes help the cold sore go away and other times it may make the cold sore worse and even burn the skin.
A better home remedy for getting rid of cold sores it to put some apple cider vinegar onto the cold sore.
The apple cider vinegar contains antibacterial properties which can kill off the virus causing the cold sore.
You can also apply some Abreva, Aloe Vera or even chill the cold sore with some ice cubes or cold compress to get rid of the cold sore.
Applying some salt to the cold sore can help get rid of the cold sore although I wouldn't leave the salt on the cold sore overnight.