Combine the balsamic and red wine vinegars, raisins, onion, garlic, brown sugar, cloves, cumin, celery salt, rosemary, and anchovies in a large nonreactive saucepan and cook over medium-low heat until the mixture has reduced by one third. Pour through a fine-mesh strainer twice or until you have a nice smooth sauce; discard the solids. Let cool, then cover, and refrigerate in a jar for up to 1 month.