1. In a bowl of hot water, add baking soda and let melt completely.
2. After baking soda has dissolved, soak in a sieve for 10-20 minutes (cover the sieve with water).
3. Use the old toothbrush to brush the soaked filter directly.
4. With a few swiping, the greasy tea can be removed off the filtering network easily.
Tip: clean the filter screen had better use a toothbrush, because the filter net has a hole, with other tools such as vegetable melon cloth, brush the hole.