Peel potatoes, and cut into 4-by-1/4-inch matchsticks. Place in a large bowl, and add enough water to cover by 1 inch. Transfer to the refrigerator for 12 to 24 hours.
Drain potatoes very well 20 minutes before frying. In a medium stockpot, heat oil over medium-high heat to 325 degrees. Working in batches, add the potatoes to the oil. Blanch for 3 minutes. Use a slotted spoon or a skimmer to transfer potatoes to a baking sheet. Allow the oil to return to 325 degrees between each batch.
Heat the oil to 375 degrees. Working in batches, add the blanched potatoes to the oil, and cook until golden brown, about 3 1/2 minutes. Use a slotted spoon to transfer potatoes to a paper towel lined baking sheet to drain. Allow the oil to return to 375 degrees between each batch. Sprinkle with salt, and serve immediately.