Can. Walnut shells boiled once after the water, the water can soak feet to go foot fungus. So it can be used. Walnut for the walnut family, walnut plants, trees, up to 20 to 25 meters; trunk shorter than other species, the crown is broad; bark gray-green when young, old, gray and longitudinally lobed; branchlets are glabrous, glossy, peltate bearing glands, gray-green, later brownish.