Diamond D and his Voodoo Tea

You'll see it at every Slacks gig - before the show and on the breaks, the consumate musician caring for his instrument. Diamond D screws open his little blue thermos and carefully pours out a few drams of hot tea. He sips it meticulously. "It's for my throat," he says softly. "I can't sing without it."
But this is no ordinary Oolong or English Breakfast. No no, it's homemade by Mr. Wilkerson himself, according to strict rules and ancient rituals. What's in it? I have no idea, but I know the recipe has changed - no, evolved - over the years. I know that D frequents a local Chinese market to obtain certain special leaves. I know he also travels to Salem, Massachusetts (home of all things wicken) to procure a special additive. I know it takes over 30 minutes to steep a small batch.
One night I asked him what was in it, and he gave me a pretty long (but clearly incomplete) list, including ginger, honey, and licorice. "Any voodoo?" I asked. "Not yet," he replied with his signature mysterious sneer. I guess it hasn't come to that yet. I was going to ask him for a sip, but I'm afraid.
So next time you see Diamond D sipping his tea, ask him what's in it, maybe he'll tell you. And then ask if you can have a taste. I dare you.