Buttermilk is high in sugar at 12 grams per cup, so I don’t use it anymore. In my pre-BSD days, I used to make a killer blue cheese dressing/dip with it, and it called for 1/4 cup, so you could make something like that and use it as a dip for pork rinds, buffalo wings or even as a salad dressing. Just blend 1/4 cup buttermilk with 1/4 blue cheese, 1/4 cup mayonnaise and 1 tablespoon (about 15ml) of lemon or lime juice. Stir in one minced garlic clove, 5 grams of finely chopped chives and salt and pepper to taste.
That makes quite a thick dip. If you want to use it as a salad dressing, add a splash of chicken broth and whisk it in with a fork. Put your salad greens in a large bowl, pour, say, half the dressing on top and toss it thoroughly.