The Bug-A-Salt 2.0 fires common table salt at house flies. It is much more fun, and effective, than a flyswatter.
I live near the beach, seaweed and dead things attract a lot of flies. Somehow, the flies always know to land in places where I can't hit them with a swatter. I was thrilled when a friend gave me the Bug-A-Salt 2.0 as a fly killing gift. Corners, windows, wherever they land they Bug-A-Salt will end them. I've even popped a few in mid-flight.
This anti-fly weapon is easy to use. Just pour table salt into the reservoir, rack the pump and release the safety. The video gives some good tips, but also mentions that you should not modify the Bug-A-Salt. That seems like an invitation to clever folks, but be careful.
Bug-A-Salt 2.0 via Amazon