I'd like to see this test repeated, but with investigators smuggling bottled water instead of weapons. I bet the TSA would have a much higher success rate with that.
It would be trivial. Go buy a large bottle of contact lens solution, empty it, and re-fill it with water. Tell them it's contact lens solution and you're all set.
Doing this with explosives may be more difficult, what with the fancy chemical detectors.
You'd have to buy the bottle after screening, not before.
You're only allowed to take 3.4 ounces through screening unless you have a medical need. I'm not sure people have a medical need for more contact lens solution, even on long flights.
Maybe the TSA rules changed? I'm going by what they said on their website:
Contact lens solution is considered "medically required", and "reasonable quantities" is sufficiently ill-defined that nobody really cares. I'm sure if you had a barrel of the stuff they might ask questions, but a standard 14oz bottle from the store gets at most a quick swab and you're on your way.
That swab is what makes this scheme impractical for bringing dangerous liquids, of course.
Bruce Schneier once took two 12 oz bottles of "saline solution" through security to test that.
>Later, Schneier would carry two bottles labeled saline solution—24 ounces in total—through security. An officer asked him why he needed two bottles. "Two eyes," he said. He was allowed to keep the bottles.
That probably has to do with the detection tools they have. I imagine a bomb is hard to spot if it doesn't look like this: http://i.imgur.com/WyY4d4f.png