DF5000 is not an insecticide and does not kill flies of any species. DF5000 is an enzyme product that breaks down organic matter that flies breed in. If the Phorid flies and Fruit flies are breeding in drains that have a buildup of organic matter, DF5000 is used it can help get rid of those pests.
If the flies are not coming from your drain then we do carry Natural Catch Plus Fruit Fly Traps that will attract and trap adult fruit flies flying around the room. We also carry a product called Clean Air Purge which is an aerosol you can spray in the center of the room and it will knock down any adults flying around.
The DF 5000 will break up organic matter in the drain disrupting the breeding site for drain flies, but it will not remove clogs. We recommend that you also snake for hair removal in the drains.
Yes, you can use the DF5000 along with the Gentrol Aerosol IGR. You would want to coat the outside of the drain at a 360 degree angle, and use the aerosol straight down the middle of the drain. Please let us know if we can be of any further assistance.