I bought this on amazon: http://www.amazon.com/Dupont-Advion-Cockroach-Bait-Tubes/dp/B00
This is actually the first thing that ever worked for me. The roaches were
gone in one week and it has been three months and they are not back yet. The
toxicity is very low (just high enough to kill the roaches, think about how
much they weigh comparing to the weight of human). If you are concerned,
cover all the cookware and plates in your cabinet. Roaches should be gone
really soon.