Insecticides
Though insecticides still remain the most preferred way of killing cockroaches, I went in for a more, shall we say organic, method. Somebody had told me that sprinkling boric acid in all the openings where cockroaches enter your home, makes them poison themselves. This did work to an extent for the roaches that crawled in. However, after a day or two, the roaches got smarter and the boric acid no longer deterred them. Please note that boric acid is not a good idea if you have cockroaches in your home that fly.