http://sodiumbicarbonate.imva.info/inde ... d-and-flu/ - bicarbonate salts
Fresh ginger in food and warm water (a la tea), fresh lemon on food and in tea. Garlic if you can stomach it.
The neti pot nasal rinse is great for getting rid of nasties that like to lurk in the nasal passages.
Saunas can help as they slightly increase body temp which can kill nasties in the body.
If you take vit c use natural stuff like acerola and camu powder.
Lots of water, pinch of him salts in it, lots of green veg and avoid foods that require lots of work by the body to process (meat, processed foods, dairy, alcohol, coffee etc); this diverts the body's resources and energy away from getting rid of nasties in the body and making you better.
No real supps to speak of (except bicarb salts) will shift it without a slight lifestyle change.
Hope that helps