Slice the potatoes about 1/16-inch thick on a mandoline. Put the potato slices in a large bowl of cold water and agitate the water to release the starch. Drain and repeat until the water remains clear, about three more times. Line two baking sheets with paper towels and spread the potatoes on top in a single layer; pat dry thoroughly.
Fill a large, wide pot with 2 inches of oil. Heat the oil to 315 degrees F over medium-high heat. Fry a small batch of potatoes until golden brown and crispy, 3 to 4 minutes. Transfer to a paper-towel-lined pan with a large slotted spoon and sprinkle with chicken salt. Repeat with the remaining potatoes, returning the oil to temperature between batches.