I have had, myself, definite success tamping down, and heading off at the pass, semi-regular and ever potential infections that want to develop around a loose rear molar I have, by using a few drops of Oreganol (concentrated oregano oil) along with a half-dropper full of something called Gum Guardian, an herbal mouth rinse. Good combo, and Oreganol is pretty impressive. Like the garlic effect description in the linked article, it burns and seems to kill everything, and I have learned that I need to pull the fluid mixture around in my mouth very aggressively to get the concoction below/above the gum line, where the infection is.
When already ‘horse has left the barn’ infected, I also have done sea or himalayan salt water rinses (I hear sea is better for this), and c. silver (separately). The salt clearly helps, not sure about the silver, but the oreganol seems most potent of all. I just rinse my mouth aggressively most days now, and so far, have kept the tooth in my mouth, and most new infections at bay.
Am going to try the garlic remedy in this article, and the tea to see about its systemic effect.