Scrub the potatoes and dry completely. For each potato, tear off a piece of aluminum foil large enough to wrap around the potato completely. Prick the potato all over with a fork, then place it in the center of the foil. Drizzle with 1/2 teaspoon olive oil and sprinkle with 1/4 teaspoon kosher salt. Rub the salt and oil over the surface of the potato, then wrap tightly with the foil sheet. Place in your slow cooker.
Cook the potatoes on high for 4 to 5 hours or low for 8 to 10 hours, until soft. Do not overcook, or the potatoes may become soggy. Remove and carefully unwrap (the potatoes will be hot). Split and top with cheese, chives, bacon, and Greek yogurt as desired.
The cooking time will vary based on the size of your potato. Large potatoes will need longer, while smaller potatoes will cook more quickly. I think this method would also work well with other types of potatoes (such as Yukon gold) or sweet potatoes, so feel free to experiment.