It requires very small amounts of War Paint to kill and repel flies. Small amounts of War Paint are placed on the horse only where flies tend to congregate.
War Paint, when applied to the horse, attaches to the hair of the horse and slowly releases the insecticide over a period of weeks. Full body fly control does not usually occur until 1 to 2 days after the application. The reason for this is it takes awhile for the formulation to release the insecticide onto the horse's hair.
Because War Paint is not only an insecticide, but also an effective repellant, you will notice that in the case of face fly activity, the repellant activity of the product will be apparent within hours if not immediately after application.
After a period of one to two weeks, as the insecticide is released onto the horse's hair, you will find that War Paint becomes powdery and will fall off the horse's hair leaving no adverse effects on the horse's appearance.