Since I really don't like poison, and I am afraid the carnivorous plants I have don't either, I started to look for better ways to catch cockroaches. Also the idea of dead roaches in places unreachable and slowly rotting away is not attractive.
I found a site with nice cockroach traps, based on glue. But the problem is that those are probably hard to get in Mexico, if at all.
Another site described a simple trap, using a plastic bottle, and I decided to give that one a try.