allegations of bitcoin being used for untraceable money laundering

allegations of bitcoin being used for untraceable money laundering

Gold appears opaque on an airport x-ray, and opaque blocks get your luggage opened and hand-checked - as would (e.g.) a gold-lined suitcase. Your box is big enough to be worth a manual check, and most countries (USA included) require you to declare high value items if you're crossing an international border, which would cover your gold box.

Fundamentally, the state is well aware of the risks of gold smuggling, and already knows how to catch it for any commercially viable amount - you'd have to carry under $10k at a time to even have a chance of slipping the net.