Rubbing papaya soap over an insect bite or wound can help relieve pain, itching, swelling, and redness. This is because papain can reduce inflammation and promote wound healing. Also, some insect venom contains peptides, which are the building blocks of proteins.Papaya soap is rich in vitamin C, an antioxidant that can reduce irregular pigmentation and stimulate collagen production. The soap also contains vitamin A, another important nutrient for the skin. It promotes the production of new skin cells, and may help reduce dark spots, blemishes, and scars.