Several short-lasting aerosol insecticides contain the active ingredients pyrethrins or resmethrin. They irritate cockroaches and can flush the pests out of their hiding places and force them into areas treated with a residual insecticide. This flushing action also is useful to determine whether or not cockroaches are present. Flushing agents, however, can drive them into previously uninfested parts of the building. When applied to dry locations, they have a longer useful life than residual sprays.
Some dusts contain conventional insecticides, while others contain no organic chemicals.
It can cause skin irritations if improperly handled, and it will harm house plants. Apply boric acid only to hiding places and runways. It is slow acting. Do not expect complete control for at least one week after application. Boric acid is among the best cockroach insecticides.