Removes Oils Fast: Tecnu Outdoor Skin Cleanser is your solution to the misery of poison oak, ivy and sumac. Cleans and decontaminates by removing the invisible, oily poison from skin and clothing. Cleanse After Exposure: When you return from outdoors or finish handling pets or tools that may have poison plant oils on them, cleanse your skin with Tecnu as soon as possible, within 2-8 hours. This normally washes away the urushiol oils before they can produce a rash. Cleanse the Rash: Tecnu stops the rash from spreading by removing the irritant, allowing the skin's natural healing process to begin without possible recontamination. Other treatments simply cover up the symptoms.