Sinus Infections: My grandfather was an herbalist during the early 1900's. His remedy, which I've always found effective, was to boil a large sliced onion with a tablespoon of coarse salt and enough ACV to cover. Bring to a boil then reduce to a simmer got 20-30 minutes. Breathing these vapors will sting a bit but is helpful. After cooking you can use 1-2 Tbs of this in warm water to drink or simple sip the straight concoction once cooled. It keeps well for a few weeks when refrigerated. Onion juice contains a natural antibiotic which compliments the mucolytic effect of the vinegar.