For killing flies/wasps inside the home- Use Windex! Often times, flies or wasps end up on your windows or glass
doors. I spray them with Windex (although any glass cleaner would work).
Then the insect becomes delirious and falls. I spray them again so they
can't fly off and then I smash them with a paper towel. If the insect is
on the door, I do give them one chance to live by opening the door to let them
out. If they don't go out, they're mine!