I was always under the impression from what we sell onboard the aircraft, that it is fine for it to go through Flight Connections in the sealed bag with the receipt sealed inside, but as for going Land Side, then back through to Air Side, I am not sure.

Not wanting to put the dampeners on it, but if you are going Land Side and mixing with members of the public, they could use the excuse that the item could have been switched and the receipt placed into new sealed bag etc... So, I would be quite cautious.