That dustin-mizer thing looks frickin’ awesome! Where did you get it?
I’ve been using a “puffer style” pump duster, which works OK but isn’t exactly ideal. Sometimes it belches out too much dust at once.
I answered my own question with a quick Googling...
For the interested, Google ‘dustin mizer’.
Here’s the first hit:
http://www.gardenharvestsupply.com/productcart/pc/Dustin-Mizer-Garden-Duster-with-Deflector-p87.htm
Search on the net for it. They are a little expensive. I bought mine at a local seed and feed store. I went in looking for the old style pump sprayer - the kind I remember gardeners used to use to dust sulpher on roses and such. The guy said he stopped selling them because he got to many complaints and showed me the Dustin-Mizer.