I've had some in my van and had the opportunity to try a large variety of things, including essential oils, various pesticides, cleaning, etc. What worked for

I've had some in my van and had the opportunity to try a large variety of things, including essential oils, various pesticides, cleaning, etc. What worked for me and was quite radical was steam cleaning. It takes a lot of time to be thorough, but it kills them very quickly, includes the eggs, and can safely go almost anywhere (except on my poor books)