Pneumatic Air Blaster for Sugar

My company is looking to find an economical and efficient way to coat a frame of roughly 300 rock candy sticks with a pneumatic air gun with a mixture of crystalline sugar, crystalline citric acid and powdered malic acid.  Our engineer (who is a moron of the highest degree when it comes to food safety) said we could just use an abrasive air powered gun like this one:

https://www.harborfr...-kit-59490.html

I am covering my bases and I talked with Harbor Freight technical support for over half an hour and they said that (of course) this item isn't recommended for food applications.  

So, I am trying to find a food safe alternative, I talked with KREA Swiss and their spray guns are only for liquid or oil solutions.  Does anyone have any recommendations that are food safe and preferably pneumatic powered?  

I've spent 2 hours trying to find something but am turning up no leads.

How hard would it be to DIY with food safe construction?

It's basically just a food safe hopper, a SS "barrel", and trigger valve. You'd lose the economies of scale that Harbor Freight has, so materials will probably be more than the $30 Harbor Freight item linked. It would also be much easier to disassemble (and therefore clean).

Not sure but the engineer has already had the two maintenance guys hook up airlines in the room this will be done in.  And they said that a test where they used that abrasive material air blaster "worked great" (they aren't going to sell the candy they tested it on of course), but I told them they should've come to me before they tried that because now they've "fell in love with that" and now I have to basically get them a solution that works within those parameters.

Talk to your maintenance guys. I've got an awesome maintenance supervisor that loves making his own stuff.

I've also gotta ask, your compressed air is food safe, right?