In a large skillet over medium high heat, fry pork sausage and onion until sausage is evenly brown and onion is soft, about 10 minutes. Drain and allow to cool slightly.
Crumble sausage mixture into a large bowl and add drained sauerkraut, mustard, garlic salt, pepper and 2 tablespoons bread crumbs. Combine cream cheese and parsley, and mix into sauerkraut mixture. Refrigerate for 1 hour.
Heat oil in deep-fryer to 375 degrees F (190 degrees C). Shape sauerkraut mixture into 3/4 inch balls. Coat balls with flour. In a small bowl, whisk together egg and milk. Dip floured balls in egg mixture and then roll in remaining bread crumbs.
Deep fry in batches for 2 to 3 minutes or until golden brown. Drain on paper towels and serve hot.