I think trying the soapy water routine first would be my recommendation. (see my first post above) It's non-toxic and also the bugs don't get resistant to it as they do to insecticides, because it kills them mechanically, not by poisoning. I always try the soapy water first, and it usually does the job. Then break out the big guns, and go spend big bucks on poison only if I must.
The DE was a preventative measure, after the initial big infestation is taken care of, which I sure hope it already is. Genny?