There's not much you're going to do to get lower rates on international shipping. It's expensive, and the USPS only sets the piece of the shipping rate that applies to shipping within the US. The rest of the rate is determined by the postal service that the package is going to end up with.

If you're shipping the diatomaceous earth, make sure the package is SEALED within the box. Double or triple bagging within the package is a good idea, and placing a sealed box within another box is even better, in addition to triple bagging.

We get a little jumpy about white powder for some reason.....