If you refer to ocean-going shipping containers, they have large rubber gaskets at the doors, but are also vented various points, so more would be required to "seal" one.
So I suppose my questions would be how much sealing are we talking about, and can we damage the seals in the process.
If the door must be sealed I would recommend any number of adhesives could be applied to actually glue the door seals shut. It would require the seals be cut at the destination, but would provide positive proof that it had been sealed enroute.
Or you could use commercially available lead seals that are serialized, pass the serial number to the recipient.
Let us know more and we can help better.
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container sealing 
Re: container sealing
