これさえ読めば安心! How to Get Tea Stains Outの対策を順番に解説します。

Okay, for the nuclear option: from stained to “I’m never using this mug again.” Soak the cup in a solution of one part bleach to five parts water for an hour. This is a last resort, people. Bleach is harsh—it can damage glazes, and it smells like a swimming pool’s angry cousin. Never mix bleach with vinegar, or you’ll create chlorine gas and become a science experiment gone wrong. Rinse the mug like it’s radioactive—three times at least. Then, wash with dish soap. Your mug will look newborn, but you’ll feel a tinge of villainy.

How Remove Tea Stain From Clothes at Jose Boyd blog

The lemon and salt secret

My grandmother swore by this, and she had teacups that survived the Victorian era. Cut a lemon in half, dip it in coarse salt, and rub it onto the stain like you’re buffing a car. The acid from the lemon and the abrasiveness of the salt work together like a buddy cop movie—one cracks the wise, the other throws the punches. Rinse, and then shine. This method smells amazing and leaves no chemicals behind. Plus, you can use the other lemon half for your gin and tonic afterward. Priorities.