Saw this in a hunting mag this month, thought it was interesting, and a way to save money... make your own scent blocking spray: 2 cups 3% hydrogen peroxide, 2 cups distilled water, 1/2 cup baking soda, 1 ounce unscented shampoo. Mix all ingredients in a bowl until baking soda disolves, then put into a container with a loose fitting lid for 3 or so days. And it's ready to go!