The soda blasting process is very laborius, in that it takes a long time to do it right. Think of it this way: if you've ever seen something sandblasted? The sandblasting is pretty darn quick in removing paint. Soda blasting takes much longer. However, soda does NOT harm the metal at all, whereas sandblasting can pit the surface somewhat. There are other tpes of media too, such as crushed walnut shells. But overall, for maintaining the integrity of the metal, soda blasting is the way to go. This is simply baking soda...the same stuff you may have a box of in your refrigerator, brush your teeth with, etc.
I bought a small portable rig from Harbor Freight (about $100) and figured I'd start by doing some small parts on my own. Bad idea, at least at the time I started (mid-summer). Soda is VERY sensitive to humidity, and the least bit of moisture will clog (ie: disable) a machine. This is where my buddy came in: he is a professional soda-blaster, and he has a $32,000 portable rig. His rig has multiple dryer units that take ALL the moisture out of the blasting lines, all the time. He worked on my Jeep for about 8-hours straight, in order to get it done. The process is that he'll start blasting an area about 1-foot by 1-foot. This took about 10-minutes to do this area (just to give you an idea of how long it takes).
The ONLY thing soda does to metal, is slightly changes the pH values of the surface metal. However, this is temporary. All you have to do is to wipe down the parts with a solution of 50/50 vinegar and water. This vinegar neutralizes the negative pH that the soda temporarily has on the surface. Then you are ready to prime/paint! The GOOD thing about the soda changing the pH of the metal? Until you are ready to wipe it down with the vinegar, even though it is bare metal, the metal will NOT get any surface rust at all.
Let me know if I can help further.
Edit: any blaster requires a very large compressor, but the equipment itself to do the blasting is rather simple...a hose, nozzle, and a hopper for the soda media. That's where my friends rig is awesome: it holds 100-pounds of soda at a time, has a huge diesel engine and compressor, etc. Worth every penny to hire out this job and have someone do it for you....