Home-made soap & oil spray for insect control MIX: 2 1/2 TBSP cooking oil + 2 1/2 TBSP baby shampoo Mix well in 1 gallon of water NOTE: Shake well before and during application. Water the plant well the day before you spray. Do not spray during the heat of the day in full sun. Reduce potential injury by rinsing the plant with fresh water a few Hours after the soap spray application. Thorough coverage of the pest is necessary so spray both sides of The foliage thoroughly until it drips from the leaves. Spray every 5-7 days as needed.