In a very large, heavy pot with a tight-fitting lid, heat 1/4 cup
of the oil
over high heat until it's very hot, just to the point of smoking. Add a handful of collards, water droplets still clinging to them, to the pot (be careful, this will sputter). Stir vigorously with long tongs or a wooden spoon until the greens are wilted. Continue adding handfuls of wet collards, stirring until they wilt before adding more. Add the salt and the remaining 1/4 cup oil and stir well. Reduce the heat to low, cover the pot, and let the greens braise for 15 minutes.