Contact this guy at http://www.soda-blast.com His name is John and he is very informative. He can give you answers even if you don't buy his stuff. I talked to him and bought some different types of soda from him. It's not as easy as just sandblasting, but the results are very good. Depends on what you're going to blast. Sometimes a wire wheel or a sanding disc is better if there is room. I used a combination.
We have one at work. They are great for the right purpose. It will not remove anything rubber (silicone, seam sealer, undercoating, grease,...). It will strip paint off great though. It doesn't do as good as sand on rust either. It will just take the flakes off and leave the rust. I use ours to strip paint off of parts. It is the only thing we can use on aircraft parts that doesn't remove any metal or heat it up when blasting other than liquid stripper.
Depending on your application, you might try other media that you can blast through your "regular" sand blastler.
My favorite light duty media is corn cobs. Yup, that's right. Just cleaned the remaining greasydirt and blue paint from my timing chain cover with corn cob media. Seemed to leave the aluminum completely alone. ALso have used it for small pot-metal and plastic parts.