What's the procedure to hand carry samples into Brazil?

What's the procedure to hand carry samples (non commercial, but for show/display) into BR? Can anyone share experience at airport?

Since Brazil does not accept ATA carnets yet, I'd like to learn more about the process to hand carry samples that will be temporarily in Brazil for show. How to prepare traveler for declaration and payment of duties at airport.

I'd like to prevent samples from been detained.

Thanks,
Claudia

Claudia
suarez