I like you have found out would have thought the salt would sting and wouldn't do much good. When I was nursing we sometimes gave a little piece of an effervescent Vitamen C tablet for a dirty coated tongue but the bi carb, Natural white yogurt no flavourings, and Nystatin are the cure I suggest for your digestive system  as it will be right through your system even though its just your mouth you are aware of at the moment.
Hugs
Angela xxx