There are plenty of other products that work as well or better than DE. THere is a lot of inaccurate hype about DE. It is a good dessicant, but not as good as a few otehrs such as Sweet PDZ. As an insecticide? Not very useful.
I checked your link and whew that's expensive for 4 little bags! I just had a 50# bag of food grade DE delivered for $24.00 plus the shipping for a $56.00 total. Do a search on Amazon.com and you'll find much cheaper