I love it... Cockroaches are survivors. When I was in grad school my lab was in a subbasement in a 100 year old building. We had huge cockroaches...

One of my colleagues caught some and put them in one of our lab freezers and forgot about them. Months later we remembered the jar... took it out of the freezer. Cockroaches thawed out and seemed to be fine... very active, almost like nothing happened.

Other experiments were performed as well... anyhow, cockroaches are hard to kill.

Diatomaceous earth is very effective at killing them. It's fascinating that they're so robust, but just a little inert powder can kill them. Though to be fair, at their scale, it may as well be a pile of razor blades.

One drop of dichloromethane does them in super fast. Their body metabolizes it into Carbon monoxide. A bit of a wake up call for those of us using dcm (our bodies do too, but less quickly)