[mothered]

If I initiate a return for a laptop and box an equal weight of dry ice and send that back, how will that help me?

Upon receiving an empty box, they'd believe the laptop was stolen In transit.

On the grounds they're liable for loss of goods, they'd cover all costs by way of refunding your order.

Why not just send any random crap item that also weighs the same?

How will you explain a totally different Item (that's not part of their Inventory), ended up In the return?

I know dry ice sublimates and will eventually all disappear, leaving the box empty, but what is the point of this? Won't they realize they've been duped once they open the box?

As stated above.