Yup, I have. I just brought books with pictures, common and latin names and marked the paragraphs that said they were "harmless".
They asked me to come in the customs building and show them the snakes and literature. Then they asked for the latin names and looked them up on a long list. After that they asked me a few questions like "what do they eat?", and "what are you going to do with them?". Just for their own curiosity.
It all went pretty smoothly.