I spray with HOME DEFENSE around windows, doors, any cracks, baseboard, then when that's dry I use Boric Acid (mix with a little sugar), put Boric Acid under all sinks around pipes, closet corners wherever they may enter. 20 Mule team Borax also works (old detergent) also mix with a little sugar, kills ants too. After a few weeks you should be ok. Mixture is ineffective if it gets wet. Bay Leaves will keep them away also. I use all of these methods, have not seen a cockroach (maybe dead) in almost 1 year. One more thing sprinkle mixture behind stove, under all kitchen appliances and in garage that's where they like to nest.