Wash and scrub the potatoes. Stab each potato with a fork 6-7 times (this will prevent them from exploding while they cook). Drizzle olive oil on each potato and rub in with your hands to cover the entire potato. Season with salt and pepper and then wrap each potato tightly in tin foil. Place in the slow cooker and cook on LOW for 8 hours or until soft when you press the potato with your finger.