To help relieve the pain of sinusitis, both Patrick Quillin PhD, in his bookAmazing Honey Garlic and Vinegar, and Cynthia Holzapfel, in her book Apple Cider Vinegar for Weight Loss and Good Health, suggest drinking a glass of water with 1 or 2 teaspoons of ACV added, every hour for 6 to 8 hours.
For sinus headache, Marie Nadine Antol, in her book The Incredible Secrets of Vinegar, recommends adding an eight of a cup of ACV to a cool-air vaporizer and inhaling the infused-air directly for 5 minutes.
After that lie down for 20 minutes and wait for your respiratory passages to clear.
For excess mucus in the nose, throat, or sinus cavities (post nasal drip), try a solution of warm water and 1 to 2 tablespoons of apple cider vinegar. Place a small amount in the palm of your hand, block one nostril, then place the other nostril into the vinegar solution and sniff hard. You'll experience the disinfecting and mucus-cutting benefits of apple cider vinegar deep into your sinus cavities. Let the solution run down the back of your throat then spit it out. After that, repeat with the other nostril.