If you're going to post this as an actual recipe, you might want to drop Terry Whitefeather an email and ask him what exactly he put in that colds banishment tea. He used to whip up his own custom herbal mixes like that all the time to sell at the Eye (and may still do a few). All I recall about that particular one is that it had echinacea in it.
Edited to add: I found an old flyer of his which lists the ingredients as echinacea, coltsfoot, ma huang, eucalyptus leaves, horehound herb, liquorice root, wild cherry bark, and peppermint leaves. It doesn't say how much of each is included, though.
Try him at firstname.lastname@example.org and see if he remembers.