Season ducks with salt and pepper and place in a shallow dish. Combine Jack Daniel’s, orange juice and olive oil and pour over ducks to coat. Cover and refrigerate for 4 to 6 hours, turning occasionally.
To prepare sauce, combine all ingredients in a saucepan over medium heat and bring to a boil. Reduce heat and simmer for 20 minutes to blend flavors. Season with salt and pepper and allow to cool. Sauce can be cooled and refrigerated for a week or two. Remove ducks from marinade. Grill or roast until medium-rare. Baste with sauce just before done. Serve with additional warmed sauce on the side.