Although commercial wasp spray or other wasp killing products are very effective at addressing a wasp or hornet problem, many people are concerned over the toxic ingredients or chemicals that are used to make these products. Very often, commercial sprays can kill more than just wasps, destroying the lives of some beneficial insects, in some cases plants, and in the worst cases they can harm family pets. It is because of these concerns that the creation of homemade wasp killer has become very popular.
You can start by using products that come in spray bottles, but are not meant for insects. The most effective are hairspray and WD40. Both these products have chemicals in them that will kill wasps well, and they can also be sprayed onto the wasp nest, soaking the nest and killing the source of the problem.
Another easy homemade killer is to mix very spicy peppers or chilies in some water. A potent pepper spray can be effective at killing wasps. You can make it more effective by mixing some detergent or peppermint oil in it. Some simply mix a tablespoon of peppermint oil with a tablespoon of detergent and mix this with warm water to create an effective wasp spray.
The most popular type of of homemade killer is a mixture of soap and water. This is actually an all around insect killing spray. Diluting soap in some water is very effective at killing insects because they are affected by the mild chemicals in the soap. For wasps, diluting five tablespoons of liquid detergent in a medium sized spray bottle that is filled with warm water is an effective killer.
When using any wasp spray or killer, be sure to spray the nest. Soaking the nest with your spray is the best way to eliminate the problem quickly since you're cutting the source. Do this at night when it is cold because it is at this time that wasps are dormant and are all in their nest. Be sure you wear protective clothing (you can just wear several layers) so that any wasps that come out to defend their home can't hurt you.
Apart from using a wasp killer and/or wasp traps, be sure you also practice wasp prevention. This is especially important if you notice that you have wasps every year. One way you can prevent wasps from nesting in your home is to use fabric softener sheets to line areas in your home which may be conducive to nest building. Wasps don't like fabric softener so they will stay away from these areas. You can also choose to coat the areas with some liquid fabric softener.