I have used raw garlic in the mouth a few times when confined to the house with really bad sore throat, head colds and such.
The thing is. Does one feel really bad enough to go thru the actual use of a clove of raw garlic in the mouth for any period of time!? It is pretty tough to do for any extended period.

One could ask:
"Do I feel bad enough to put myself thru that?"
Try L’Aïgo Boulido
“
In addition to its reputed medicinal virtues, this amusingly titled soup is delicious and tangy.”
This Provençal infusion is said to have extraordinary virtues. Nothing can resist it: hangover, illness, child birth - there can be no convalescence without “boiled water.” There’s an old proverb that says,
Aï
go boulido sauova la vida (Boiled water saves your life).
1 quart water
salt
12 - 15 garlic cloves
1 or 2 Turkish bay leaves (or one small/med California Bay Laurel leaf)
1 or 2 sprigs sage
1/4 cup extra virgin olive oil (a good French oil can be nice here)
a couple - three slices of good quality day old white bread
freshly grated Gruyère or Parmesan cheese
Boil water in a non-reactive saucepan, add salt to taste, then add garlic. When water returns to boil, boil gently for ten minutes, then add the bay leaves, sage, and a dash of oil. Let cook a few minutes more, then remove pan from the heat, cover, and allow the soup to stand for about ten or twelve minutes to infuse the water completely. Then strain the water.
Put the bread in a warmed soup tureen, cover with grated cheese, sprinkle with remaining oil, and pour in the strained infusion.
Inspired by a recipe from Joséphine Besson, the original of which can be found in the book
La Mère Besson “Ma Cuisine Provençal”
This is but one of numerous variations of the concept. Some don't include cheese, others include eggs, etc. They all contain plenty of herb-infused garlic broth.