I have used diatomaceous earth for years on ticks on the dog, and on carpenter bees. Squirt it in a carpenter bee hole with a syringe, in about 20 seconds 3 dying carpenter bees come tumbling out. I like to watch 'em writhe around while they die. Takes about 3 minutes.
What is wrong with sprinkling it around a vacant house? Let it set for 2 weeks and then vacuum it up.
