Great research!! And It´s just a straw. I´m from Argentina, and what you say about the metal straw for mate Is true. But there Is more.... We even share the same straw with other people and hundreds of times!!! Isn´t that ecological? At first It´s kind of shocking but then you get used to it...

Hola Edgar, me re-gusta la idea. Acá en Argentina, hay un prototipo de algo que puede tener algo que ver con lo que vos estás planteando.

http://www.emium.com.ar/emium_usos_y_aplicaciones.php

I liked the idea... It´s simple. Maybe car air fresheners could work as well.