Fly Spray that actually kills flies!

[LucyLocketLostHerPocket]

The title says it all. I'm looking for a fly spray that actually works. I'm plagued by big black house flies at the moment (no idea why but Windows and doors open lots), been spraying the with various Raid sprays but they just seem to shake it off and carry on. You used to spray a fly and it died, have they changed the ingredients or something? It's almost like I'm spraying them with water. I dare say they die eventually but they seem to keep flying around for ages. Any suggestions?

I have to say i've normally found any fly spray works instantly. They normally crash to groudn and then spin round in circles for a few minutes.

I don't know if it would work with flies but I usually have a ginormous can of hairspray with me at all times when daddy long legs are about. I hate them! When they come near I give them a spray and watch with rapture as their wings get weighed down.

Yes, I am aware that's a bit sadistic. I don't care though.

I always use Raid Fly and Wasp Killer and it seems to work.

Oh maybe it me then I don't like doing big squirts of the stuff because I worry about the chemicals but the can says a direct one should suffice and it just isn't unless they're dying in hidden places I haven't found yet.