It's great for sheet metal as it won't heat it enough to warp. Couple of drawbacks though, according to what I've read on some metal & tool forums, most notable being the HAMB (www.jalopyjournal.com). It will leave a residue that can cause paint bonding issues, if not removed, and it will only remove light surface rust, it won't touch heavily rusted surfaces.
A "kinder, gentler sand blaster" ? Not sure if this would be a win compared to a nylon or brass brush other than getting into cracks better.
Here's where you get your soda:
50# Medium Grade AMEX Soda Blast Media
But hey, it's something different. :unknown: