I came across this eco friendly water purifier. Seems like a traditional idea that’s come full circle. From the Merchant4 site:

Chikutan Charcoal Stirrers

Think of Chikutan as the ultimate swizzle stick. This white charcoal is made from Japanese Bamboo. White charcoal is naturally activated through a controlled burning process based on traditional Japanese methods. Use these to stir your beverage and the charcoal will absorb impurities in alcohol, tea or water for a pure taste. In Japan, you will find Chikutan sticks at high-end bars. Before use, rinse sticks under hot water. 3 piece set ($22).

I’m not sure how many times you can use each stick, but I’m intrigued by the simplicity of this concept.