[DBrow]

"Traveler's Cheques......."

Which deliberately have their own odor, sort of like Play-Doh but sweeter.

I think dogs could alert on them. Let's try: you send me 80,000 in Traveler's Checks parcel post (10s and 20s) and I'll try to fly them back to you. If I don't make it, it was the dogs that got the cash. Honest. My uncle was a high ranking official in Elbonia who entrusted me with his considerable treasury. You can trust me!

[MediaMole]

Getting travelers checks in and out of the country is simple. Buy the checks, write down the serial numbers, destroy the checks, travel, then go to an American Express office with the serial numbers of the destroyed checks and have new checks issued.