Assuming you're asking about a product called "Deer Slaying Spray", it's used to, well, slay deer. You mix it with water and spread it around your property, and it apparently smells bad to deer so they stay away.
If you're looking for a natural way to keep deer away from your property, deer sleer spray may be a good option for you. Deer sleer is made from the urine of predators, such as bears and coyotes. When applied to plants and trees, it gives off a scent that deters deer from coming into the area. You can purchase deer sleer spray at most garden supply stores.
To use deer sleer spray, simply apply it to the perimeter of your property. You'll need to reapply the spray every few weeks, or after heavy rainfalls. Deer sleer spray is safe for humans and pets, and won't harm your plants or trees.
Deer sleer is a traditional remedy used to treat a variety of ailments, including colds, flu and stomach problems. It is made from the leaves of the deer herb and is believed to work by helping to clear congestion and reduce inflammation. Deer sleer spray can be purchased at most health food stores and online.
To use deer sleer spray, simply take 1-2 sprays directly into the mouth 3-4 times per day. For best results, it is recommended to use the spray at the first sign of illness.
Assuming you're asking about deer repellent spray:
Most deer repellent sprays contain either putrescent egg solids or garlic oil as the active ingredients. Both of these have very strong smells that deer find offensive. The garlic oil will also repel rabbits and other small mammals.
To use, simply spray the plants you want to protect with the repellent. Be sure to coat the plants thoroughly, especially if they're young or tender. Reapply the repellent every few days, or after it rains.
You can also find Deer Repellent Granules which work in a similar way, by releasing their scent when it rains or when you water your plants.
To use deer sleer, simply mix the peppermint oil and water in a spray bottle and apply it to the areas where you want to keep deer away. Reapply as needed, and make sure to keep an eye on the wind direction to avoid spraying yourself!