This post by Rodale is a compendium of natural cold and cough remedies. The only caveat: there are brand names used that I would NOT recommend. For honey, use raw and wild (less pesticides, and all the enzymes intact). For salt, use any bulk salt that is natural (Himalayan pink, sea salt, etc.) because they don’t contain additives (like anti-caking agents). For black pepper, get certified organic: not sprayed, not irradiated.