[Auftot]

I have heard of people using ordinary ice, I suppose the benefit to this is that it also melts and gives the box a wet, and damaged appearance. I've never personally done it but I don't see why it wouldn't work- unless the ice didn't melt in time.

I would think the company would question as to why the box was wet and be kind of suspicious

Possibly, but if a packages do get damaged by water sometimes. And the company don't necessarily have any proof that it is your fault.

I think it's worth a try. If I ever do it I'll make a thread detailing my success/failure and how it went.