To get rid of cockroaches naturally, use baking soda and sugar to kill the roaches. Other natural items that help to kill the roaches include using boric acid or making non-toxic bait.
To use the baking soda and sugar method, simply combine baking soda and sugar, and sprinkle it in areas where the cockroaches have been seen. The content of these items kills the cockroaches when it is ingested. A similar method that isn't quite as difficult to clean up consists of making bait. Combine baking soda into a dough ball with onions, bacon grease, sugar and flour. Set the bait in similar areas, and wait for the cockroach to eat it.
Boric acid isn't quite as natural or non-toxic, although it isn't as harsh as insecticide. It is sprinkled near cracks and in areas cockroaches frequent, such as basements and kitchens. It works in a similar way to baking soda and sugar.
Another method is to have a gecko in the house that eliminates unwanted pests. Not only is it an easy way to get rid of cockroaches, but there are rarely messes to clean up. Just be sure the geckos are family pets that are well taken care of and are fed on a regular basis.