Lightly grease your slow cooker with cooking oil. Layer half of the hash browns into the bottom and top with half the bacon, half the cheese, and one-third of the green onions. Set aside some bacon and green onion for garnish and then repeat with a second layer of hash brown, bacon, cheese and onion.
In a large bowl, whisk together eggs, milk, salt, and pepper and slowly pour over top. Cook until eggs are set, approximately 2-3 hours on high, or 4-5 hours on low. Sprinkle remaining bacon and onions on top and serve immediately, with or without hot sauce.