Megadoses of Vitamin C. You can get powder for cheap at http://www.allhealthtrends.com
(they also sell oregano oil, etc.). I sometimes use EmergenC although it is pretty expensive when you are taking several grams a day. To establish your Vitamin C tolerance, you can take a couple of grams every half hour until you get loose bowels -- then you have reached your tolerance level and the body does not need more. So you would then take a couple of grams less than that per day. (i.e. I hit tolerance at about 13 grams, so I take 10 or so per day).
Xylitol. Great for dental infection and ear/sinus infections. You don't want to take it long-term, but for a couple of weeks it will help deep pocket infections, or for instance the low-level infections that can live under wisdom teeth, etc.
Swish with colloidial silver.
And keep taking probiotics and building up your good flora, which is a long-term way to fight infection, too!