I bought 6 oz boric acid from dollar store and combined all 6 oz with ½ cup flour and 1/8 cup of sugar.  I added enough cooking oil to form into balls and put them in safe places throughout the house where my pets would not find them.  I put them in drawers, cabinets, under my toaster, just various places.  It worked fantastic.  I haven’t seen a live roach since doing it.  I did have quite a few dead roaches I had to clean up, however.