Found this article very informative as well:

来源: 于 2014-12-18 18:58:06 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次

http://www.nytimes.com/2013/05/30/garden/maintaining-pots-and-pans.html?pagewanted=all&_r=0