We used to use these and sure, they draw flies and the more flies you get, the less can reproduce, but God the smell. We found PT Alpine and spray just two dots per month on either side of the window and it kills them all. Safe for chickens to eat the dead flies too.
We use horse pellets on the floor that dry up the poop so that keeps them down. When they come over by the hoards from the neighbor's horse barn, I spray two "dots" of PT Alpine on either side of the window where they hang out the worst. In a few minutes, they're all dead. It keeps working...