I'd be very surprised if they were prepared to remove potentially a still pressurised, but pierced powerlet...
It's not something you would dream of asking someone unfamiliar with CO2 guns to do.

But if you ask they might be prepared to keep it for collection & retrieval by yourself or the sender.

To be honest though, why is it your problem, if the sender has had his parcel destroyed because he tried to send a prohibited item then its his problem and not yours and you should ask for a full refund for goods not received.