Unless there is not much value in that teapot, it may worth a bit of efforts to clean it up to make it usable again.
The best way to really clean it is to scrape whatever debris there is inside with a soft edge, such as a small wooden spoon, and then wash it with water and a cloth. Yes, absolutely no detergent.
However, this is not enough. Since molds are like grass. Their roots maybe deep inside the clay material and perhaps their spores too. These things may continue to be there to become part of your tea.
You will have to go through the Yixing pot cleaning process once again, starting from boiling the teapot fully submerged in water. Read this link:
This will be destructive if yours is a finer quality Yixing pot that you have been seasoning for sometime — you’ll have to start all over again.
Accidents happen 🙁
