This is a mop sauce in the eastern North Carolina tradition -- or simply put, a vinegar-based pulled pork finishing sauce with no tomatoes anywhere near it. If you don't like vinegar, this ain't for you. It's got a healthy kick to it, and the butter actually takes care of the sweetness without having to add any sugar in.
In a medium saucepan, place two sticks (1 cup) of unsalted butter over low heat and stir slowly to melt them down.
Add vinegars. If you can't find fig-infused balsamic, you can use only apple cider vinegar, just add the extra amount. Add in mustard and Worcestershire sauce, salt and various ground and flaked peppers.
In a tea-ball or in cheese cloth, add about a teaspoon of pickling spice and close off. Place into liquids in the saucepan. You will remove this before serving or storing sauce.
Beat ingredients together. Allow to simmer on low for at least 20 minutes, stirring occasionally. Can be used as a basting sauce, or as an applied sauce right before serving the meat.