Dr McCullough said on Joe Rohan’s podcast that the best thing you can do is disinfect your nasal passages every day with 2 tsp of betadine mixed with 6oz of water. Use a nasal syringe to snort it up your nose as you spray it in your nostrils and then spit it out through your mouth. You could also use other disinfectants - you’ll need to listen to the podcast.