I'm not sure what you think that proves about whether or not a border guard would accept a metal coin that the briber claims has a value in Bitcoin. The guard could have $100 million in a Bitcoin wallet and still say, "this is some kind of bullshit trick." Why wouldn't someone try to trick a border guard like that if they were desperate.

So basically, you'd have to hope this border guard would either be one of the very small number of people (hardly a quarter of Americans) who would look at a metal coin with a Bitcoin symbol on it and decide it has value to them.

Again, seems like chickens would be a better bet.