Yes, Hairspray Kills Wasps.
Wasps, small but mighty, can be dealt with in a number of ways. For large jobs--major nests for example--a professionally formulated pesticide or even a contracted pest control service might be a preferable way of dealing with wasps. But for small jobs like a wasp in your kitchen or car, you can kill wasps with hairspray.
How to Kill the Wasp?
The process is simple: Squirt hairspray on the wasp from a few feet away. If you are concerned about staining from the hairspray, or a lingering layer of spray gumming up screens and windows, you need to think first. At the very least, be prepared to wash up any remaining spray with a damp sponge. Other than that, you simply point, squirt and watch the wasp die.
Is It Wise?
As a stop-gap solution, a quick-fix handy answer to keep in your car or kitchen--yes, using hairspray to kill wasps is a good, sensible answer, and probably preferable to keeping pesticides around the home casually. For larger jobs, the risk of failing to get an entire nest cleaned out makes it smarter to use professionally formulated products or professional services. A large job that needs to be done with children or pets around definitely should not be attempted with a can of hairspray.