After a few double vodkas I decided to throw this out there. This is not medical advice since I am not a doctor, but I do have a PhD in mixology which has merit in it's own right. I follow this protocol daily as part of my own routine.
I load up my nebulizer with 4 parts distilled water and one part food grade hydrogen peroxide.I have a pre-mix in the fridge of about 8oz.
The nebulizer creates a fine mist which I breath in about a half dozen times and hold each for about 3 seconds. A nebulizer can be bought on Amazon for about $40 and hydrogen peroxide is available at health food stores and also on-line. In 2020 I had a respiratory flu which lasted about 10 days. I have not had the sniffles or been sick since. Again this is not medical advice, it is just what I do.