Not exactly the answer you wanted, but I have tried the "Torso Track". While not exactly up to the standards of the infomercial, I have notice that it does work you abs. The results vary, but I know somewhere under my gut are some semi-toned muscles.
I regards to the abtronic device. I was tested once for Carpel Tunnel Syndrome, and they use electric pulses to measurse your response. I must say that it was not a comfortable tingle they gave me. I can just imagine what that would feel like on my stomach.
However, I too am curious if anyone has tried these products?
These do not work. You can do a search in this very forum to find a great thread on this. I, and others, gave a pretty good rundown of what these things do.
Something to think about - if these things really worked, why wouldn't NASA be using a similar device for all muscle groups instead of spending millions on weightless aerobic exercise machines? This would be a perfect solution - just put it on and float about.