A poultice is a soft, moist, substance spread between layers of gauze or cloth and placed hot or warm onto a body surface. This helps blood flow and reduces pain. You can make a poultice for back pain by placing the paste of chopped herbs that have been lightly cooked or mashed between layers of cloth. Apply the tepid, moist poultice to the painful site, and allow it to stay in place as long as possible. Repeat several times each day.