There's a paste that works wonders but I can't recall the name,i think it may be that cockrid that @newfarer is talking about..i applied it one year ago along the lower side of the walls adjoining the floor and my house has been roach-free since then..
Ok,apart from the occasional "lost" roach i encounter once in a while.You can tell it's a visiting roach(probably from the neighbors or wherever just foraging for food)coz it doesn't know where to run to and hide.
That's when you can now finish it PAP! using Njung'es method..

Starvation! Starvation! Starvation! Make sure there is absolutely no food in the house for weeks. 50% will die of starvation. The other 50% is even more important. They will migrate to the neighbours and spread the word on how life is like in your house. From then on, even neighbours' cockroaches will not drop by your house!!!

the polar regions are the only place you don't find a roach.
Cube Movers tasaidia wewe ku sift...teheeee

njung'e, they can never survive in the freezer itself.
Roaches can't survive in the poles. Its a fact of life.
If yours can basi hizo mende zako ni za gredi/grade!
BTW, do we have polar rats?
And why do women fear a mouse but will buy mickey mouse