Watermelon peel diuresis detumescence. Wax gourd skin not only contains many vitamins and minerals, but also contains many volatile nutrients. It can promote diuresis and reduce swelling, which is more beneficial to diabetics. So winter melon soup is best cooked with skin. Although vegetables with skins have many benefits, they should be cleaned. Generally, vegetables are soaked in clean water for 15 minutes, and then washed with clean water, which can reduce pesticide residues.