Anything that relies on the presence of trace particles is not a sufficient determiner of threat—or guilt, in this case—such that people should be denied entrance. I think the way the airport uses it, as has been said, is that if you get a hit, you are subjected to a search. They're looking for contraband. The fact that this is not followed through at CSC is really problematic.
The full body scanners, which would find things concealed under clothing and such, would be far more useful, I would think. Again, the wipes may be, but they may be subject to the same sorts of false positives, depending upon how much it takes to cause an alert.