I'm not trying to be a smart-*** either, and I appreciate the informed responses which I would summarize as:
Due to the nature of the blast medium used in soda blasting, special equipment IS required and a particular grade of soda IS required if you ever expect to get useful results.
There is a healthy tendency for many of us to be skeptical of "miraculous engineering breakthroughs" and their associated marketing hype, for example, gas-mileage improvement devices as well as garden-variety goods with flashy packaging and big price tags. Unless you understand how something works or can rely on the evaluation of a competent disinterested third party, the safe approach is to always assume it is more sizzle than steak. Not to insult you, but Eastwood does indulge in some marketing hype in pitching its products (as does everybody else).
However, to encourage our further discussion, the fact that it is a patented device has no significance to us. Patents protect Eastwood from commercial exploitation, not from hobby curiosity. We are within the entitlement granted by patent law to obtain a copy of any patent and construct an identical device for our own use. We may even tell others how to make it for themselves but we may not make it and sell it to them. The device is not a trade secret (like the recipe for Coke), so sharing the information obtained from an examination of the device or from the patent documents is not improper in any way. Likely, some shade tree mechanic will develop an improvement to the device and benefit us all.
That said, I'm not going to spend my time duplicating any expensive and useful gizmo unless it actually is just a few bucks worth of of Home Depot stuff or I have too much spare time that my wife is not yet aware of. From the information that has been provided, I will purchase the device from Eastwood should the need arise. I hope the Eastwood people are arranging demonstrations of the thing on the usual TV shows (though maybe not American Garage).