I suppose it would but I have never seen powdered Malathion it's usually a liquid product here.

Not sure how dense that powder would be and how much strain it would be on small motor for extended periods of run time ? It's essentially just an agitator sweeping product past a hole. Simple slide gate adjusts rate of application. Might take some trial and error to figure out application rate but as long as you have an idea of bushels being unloaded and amount needed you should be able to get pretty close.

http://enviropacinc.com/seed-treaters/

Applying at bottom of bristle auger does provide good coverage. Before and after pics of applying a peat based inoculant.  You can see every seed has good inoculant coverage.

(Bean 1 (Small).JPG)

(Bean 2 (Small).jpg)

Bean 1 (Small).JPG (107KB - 74 downloads)

Bean 2 (Small).jpg (133KB - 67 downloads)