This rich, creamy stew is best made with freshly shucked oysters.
Heat butter in a saucepan over medium-low heat. Add onion and celery; cook until softened, about 8 minutes. Do not brown. Add milk, cream, salt, cayenne, white pepper, and liquor. Bring just to a boil; cook, barely simmering, 5 minutes. Add oysters; cook just until edges curl, 3 to 4 minutes. Garnish with paprika; hot sauce, if using; and crackers. Serve.