Flies in the kitchen

It is impossible to keep them out if you are vending and opening windows to serve people. I keep a swatter and when I catch a break smack'em.

there are electronic bug killers that work and this is the one I use-check out the bottom of the page where it says get the bugs away. I hope it helps your friend

http://www.thebarbecuemaster.net/bbq-party.html

Most health departments do not allow the use of electronic 'zappers' to kill flies within an area being used to prep, cook or serve food, but there are UV lures that are very common in restaurant kitchens and seating areas. Their biggest problem is they work best when there is no outside light interference to detract from the UV lure.
Here is a link to one site that can provide a lot of different products. http://store.doyourownpestcontrol.c...rol-products?gclid=CNfk5dGfzLACFQUEnQodEBbhYA
Also on their site look for a product named BONANZA. It is a fly bait that cannot be used inside the trailer, but can be sprinkled outside to combat the flies and/or in bait stations. I have even put it in solution and "painted" my trash cans with it.
Hope this helps a little.