Special Import Rules for Donatons?

A friend recently got a message from a person bringing God to Nicaraguans. He has been in Nicaragua for years and told my friend that people on missions from the US can import things that will be donated. The implication is tax-free. There is no indication that the organization involved in the US is a 501(c)3 and on the Nicaragua end there is nothing beyond there being churches.

Anyone know how this works? In the past I have tried to figure out how to get some donations into Nicaragua but nothing seemed to pan out other than donations directly to the government. If I can find out how this is done, I think I could get a reasonable amount of things (such as computers) donated here.