Plus the device can be reused. If you don't have a trust relationship with your source they wont want you to send them back so they will probably let you keep it yourself but make you pay extra for the added security. But there are some people with connects overseas who regularly import <-> send money back in both directions, and then you would only need a single device and send it back and forth with drugs/money until one of the packs is intercepted. If these things are heavily tested prior to being used for actual illegal packs (as they should be!) and there are no problems detected it would make importation of bulk so much more secure. I would feel totally safe having multi kilo orders of MDMA sent to me if I knew close to 100% for sure that I would be able to tell if it was intercepted. Only issue is what if they don't open the pack until they arrest you picking it up? Would be a major change to their standard operating procedure though. They can verify the substances inside the pack without a dog hitting on it via use of terahertz radiation and such, but on the other hand there is potentially nothing stopping us from being able to detect if a pack is scanned with this sort of technology too.