Borac Acid crystals are even better than the diatomaceous earth. They are really needle-like. We learned that from our Austin 14 months in 1972-3. They (the roaches) hitch-hiked back to Alpine when we borrowed Terry Raines' horse trailer to move back. (I probably should not blame Terry, but it makes the story better.) If you don't have a free lab supply connection for the CP (chemically pure) stuff, it used to sell as ROACH PRUFE by the quart. It was about $2 a can back then. It does in ants quite well if you can get them to wrestle around in the stuff.
DirtDoc
