That's true. Natural freshwater diatomaceous earth will do that and a lot more from a health standpoint. Any clean, low crystaline silica product will work and be safe but the best quality products I have seen are from Soil Mender and DiaSource. It is the DE that is in the Muenster Natural dog food at the percentage that I recommend. Most of the retail stores that are highlighted on the web site will have these products in stock.