Re colds & sniffles & all the winter nasties:
Gargling with salt water is also good for sore throats. (I've also resorted to carrying a thermos of hot lemon juice & honey to guzzle during every break.)
When we had a woodburning stove, I would roast rosemary in an iron pan on top of the stove - it releases a nice-smelling & supposedly antiseptic smoke.
Outside of OTC remedies, one of my herbals recommends snorting a garlic emulsion - yeeeeoooooowwww! It would certainly do SOMEthing up in all them li'l sinus cavities! ;-)