I live in the US, so I haven't tried it but I think what they're saying is:
- Register Kindle with an Amazon account that has a US shipping address.
Have a second Amazon account (with the address in your home country?) buy a gift card for your first account.
- Use the apparently-foreign gift card on your Kindle's purchases to make it appear that, though you are from the US, your apparently-foreign gift card gives more legitimacy to buying books from the location in which the gifted card was bought for you, as opposed to buying US books on a foreign credit card repeatedly.