> It is possible to shoot flies out of the air. There is nothing else like it.

I mean, personally, I just spray them with Windex. (Which doesn’t so much kill them as stop them from being able to fly temporarily, at which point you can find them on the ground trying to slowly walk away, and do as you will with them.) And it has the convenient property that you already probably have a sprayer-bottle of it in your house. If you don’t, a spray bottle of {vinegar, soapy water, alcohol} works, too.

Also, these droplets of light solvents just dry cleanly off of whatever surface the droplets land on, without creating a scratch or a stain. I can’t imagine what spraying salt everywhere would do to my painted walls and (hardwood) floors.