Swanz Kokoro: Sustainable Porcelain Thermal Flask. Stain and smell free, no more metallic taste. With interior made of replaceable 100% Fine Porcelain, keeping beverages hot or cold for at least8 hours. 
This project had raised over SGD$500,000 in Taiwan alone.
It is currently launched in Indiegogo: https://bit.ly/2SfKJwT
 
Comes with 180 days warranty against breakage of porcelain. Strainer can also be added via this link https://www.swanzbrand.com/product-page/strainer-starlet-collection