I’ve been drinking plain apple cider vinegar in water every day, twice a day for about 10 years thanks to advice from a Romanian friend. Don’t get colds or flu.
If my nose/sinus ever feels stuffy (usually in high humidity of summer when very dry out) I open a small jar of horseradish paste and take a couple of whiffs! Bingo – issue solved. Gypsy is right about horseradish. If you have a head cold, eat a little Chinese mustard (not the kind comes pre-made in little plastic takeout packages) and your eyebrows and top of your head will sweat shortly. Keep it up and your cold will vanish fairly quickly.