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)