Please tell me how long it takes for to kill oral yeast infection with garlic?

Don't do it: Long enough that people will complain about your breath.

You may die first: If you actually have thrush you may want to be tested for immune dysfunction. Thrush does not generally occur in normal adults. Now perhaps if you are diabetic and on antibiotics or steroids this may happen, but good idea to be tested anyway. Particularly for HIV disease. Hope all goes well.