"A great take on a north Alabama favorite: Big Bob Gibson's white sauce. This may not be exactly like it, but it is about as close as I have been able to get it. You can substitute apple cider vinegar for the white vinegar, if desired."
Stir salad dressing, lemon juice, vinegar, sugar, horseradish, salt, and black pepper together in a bowl until smooth. Cover the bowl with plastic wrap and refrigerate until flavors combine, at least 24 hours.