Step 1: Thoroughly scrub the Russet potatoes under cold running water to remove any dirt or debris, then pat them completely dry with a clean towel.
Step 2: Using a fork, prick each potato 5-6 times all over to allow steam to escape during the cooking process.
Step 3: Rub each potato generously with olive oil and then sprinkle with the coarse sea salt, ensuring they are evenly coated.
Step 4: If desired, wrap each potato tightly in a piece of aluminum foil. This helps lock in moisture for a softer skin.
Step 5: Place the potatoes into the bottom of the slow cooker. Cover and cook on High for 4 to 5 hours or on Low for 7 to 8 hours until tender.
Step 6: Check for doneness by piercing a potato with a knife; it should slide in easily. Serve immediately with your favorite toppings.