Be thankful that you are having trouble recruiting users because a lack of users is what preventing your company's name being on the headline when someone gets executed in China or Singapore for carrying someone else’s drugs.
And even if nothing illegal is in the package, your users will still likely run into troubles when the security agent asks if all items in the bag belongs to the traveler. If you answer honestly they will likely double and triple search everything, if you lie and say no you are automatically breaking the law for making a false statement to a federal agent.