Be sure to keep  kitchen countertops,   as well as machines and appliances, clean to prevent a cockroach infestation.
Use rubber stoppers to cover kitchen and bathroom drains.
Always make sure the bin lid is closed. As mentioned before,   garbage cans   easily attract cockroaches.
Flush the drain and remove any food debris. To properly clean your drain you can count on many natural and ecological solutions such as bicarbonate or white vinegar which prove to be excellent natural unblockers.

Getting rid of cockroaches permanently is not an easy task, but prevention, natural repellents and meticulous cleaning will always get the better of cockroaches.