Lay a square of aluminum foil on your work surface and set a potato on top. Prick the potato all over with a fork. Rub it with 1/2 teaspoon of olive oil and sprinkle with salt. Wrap the potato tightly. Repeat with remaining potatoes.

Lay the potatoes in the slow cooker so they fit snugly next to each other. If you are baking 1 to 2 potatoes, set them in the middle of the slow cooker; stack 5 or more potatoes in a second layer.

Cover the slow cooker and set it to LOW for 8 hours. The potatoes will be ready to eat any time after 8 hours, but will be fine if cooked for up to 10 hours. You can remove the potatoes and eat them at any point between 8 and 10 hours. Do not leave them on the WARM setting for more than an hour.

Remove potatoes from the foil, split, and eat. When ready to eat, unwrap the potatoes, split them along the length, and top with your favorite toppings.