Well, I made one of those, too. It worked, sorta, but....
The one I made used a fairly short hose and the little boxes of baking soda you get at the supermarket. It was kinda cumbersome. Refinements will be a longer hose, and maybe a larger bulk supply of soda to siphon from.
Also, since soda isn't really abrasive, it doesn't strip much in the way of corrosion - it does some, but if it's that heavy white powdery corrosion you get on aluminum that's been sitting around for a few years, it didn't do much there. What it does do is remove grease and dirt really well and it leaves a pretty nice finish on the aluminum. But then, Gunk Engine Degreaser does, too, although Gunk is messier/more toxic to the environment.
And when I was done, I looked like the Pillsbury Doughboy - covered in white powder. :lol: Maybe if I did it in the blast cabinet... How many little boxes of baking soda do you suppose that'd take?
Here's a thread where I've documented some blast cleaning experimenting I've done:
viewtopic.php?f=19&t=618&start=10