One disadvantage of loofah insoles is poor hygroscopicity. Although the towel gourd insole has certain air permeability, compared with other materials, its moisture absorption ability is weak. In the humid environment or under the condition that the feet sweat a lot, the towel gourd insole can not effectively absorb and eliminate moisture, which leads to the feeling of dampness and discomfort in the shoes. This will cause the problem of bacterial growth and odor in the feet. Other materials, such as bamboo charcoal and water-absorbent fiber, may be more suitable for insoles that need better moisture absorption.