We're pals and both like horses, call me db.
Try this:
1. Give it a good shake, more than you think is necessary. As in it's a red-headed stepchild shake.
2. Take the top off and leave it for a few hours. Replace top, shake again. You don't want to leave the top off too long since it's a whiskey flavor, but enough to help some of the other alcohol carriers evaporate out.
3. Put in a dark place, let it be for a week, giving it a shake every day or ever other day. You don't really need to do the shaking and could leave it, but it can help speed things up.
I hope it helps, I know you probably spent a good chunk of change on it. And I could be off, but that peppery/floral/medicinal taste is usually the base or flavor carriers just not having steeped enough. Ideally you'll check it in a week and can tell it's changing, and in 2-4 you'll be very happy with it.
Putting the tightly closed juice bottle in a pot of warm water helps also.
With a whiskey, rum, or any liquor flavored juice what will evaporate if left
open is any alcohol in the mix but the flavor will remain