What kills cockroaches permanently?

What kills cockroaches permanently requires eliminating entire colonies including nymphs and egg cases, not just visible adults, using integrated pest management that combines sanitation, exclusion, and slow-acting baits for long-term control because roaches reproduce quickly and can re-enter from neighboring properties. The most permanent solution is targeted gel baits containing non-repellent insecticides like fipronil, hydramethylnon, indoxacarb, or abamectin such as Advion, Maxforce, and Vendetta, placed in small pea-sized dots under sinks, behind refrigerators, inside cabinets, and near droppings, allowing roaches to eat bait and carry it back through feces and food sharing called coprophagy to kill entire colony including hidden nymphs within days to weeks, which is far more permanent than repellent sprays that cause scattering. Permanent control also requires thorough sanitation to remove food, water, and shelter by storing all food in sealed glass or metal containers, cleaning crumbs, grease, and spills daily, taking out trash, fixing leaks, and drying sinks because German cockroaches need moisture to survive. Exclusion by sealing cracks and crevices with caulk around windows, doors, pipes, and baseboards prevents re-entry because roaches enter through gaps as small as 1/16 inch. Using insect growth regulators like Gentrol that prevent reproduction helps achieve permanence. For severe infestations, professional pest control costing $150 to $400 with follow-up visits, commercial-grade products, and warranties provides near permanent elimination plus quarterly monitoring prevents re-infestation, achieving long-term control.