Stop in for a cup of coffee
Try a local nursery. If you cannot find it there I buy it by the Gallon and can send some.. Mix it with water about 1 TBS to a quart of water with a little liquid soap in it to emulsify the oil and spray away. The only drawback I can think of it has a slight sweet garlic smell to it. 4 OZ would get you through a season. Buy 100% oil. Works on the animals also.