Soak rutabaga in salted water to cover 2 hours. Drain.
Whisk together egg, milk, and vinegar until blended. Stir together flour and next 4 ingredients. Dip rutabaga slices in egg mixture; dredge in flour mixture.
Pour oil to a depth of 2 inches into a Dutch oven; heat to 375°. Fry rutabaga, in batches, in hot oil until browned. Drain on paper towels. Sprinkle with additional salt.