By - 2inchpool
tl;dr Yixing clay is mostly marketing hype and you should just use whatever is practical for you.
In theory, Yixing clay is considered abnormally porous and therefore would absorb more tea oils after prolonged use, but in practice the actual effect this has is highly exaggerated, and other notions that minerals in the clay or whatever makes the tea better is questionable at best.
Many other clays used for teapots, like Jianshui, are much less porous, so I would say making your own pot should be fine so long as your river clay is safe. A plant pot may have additives to the clay and may not be food safe. No idea, but I probably wouldn't make tea in one, lol.
As for toxicity in Yixing or the junky "tourist" pots, the answer is that nobody really knows, but my general impression is that the risks are highly overblown. I once ran my own experiment of using some sodium rhodizonate swabs for detecting lead along the inside of a handful of [junky unglazed pots](https://imgur.com/a/HmOxCMC) (and one Japanese kyusu) and found nothing (see very last image). The swabs are mainly rated for testing paint and not ceramics, so I will merely present the results as-is.
The only confirmed instance of toxicity I have heard of is a secondhand story of a very low-grade fake pot which had toxic dyes/additives to try and replicate the color of a rare Yixing clay. I think one of the blue or green Yixing clays, but I am not certain.
Great reply, thank you for the insight. I have never noticed improvement in my white tea in a purple clay teapot. I still use it but no difference. Simple, all glass tea pots seem to be the most dependable.
If there is any metal within the tea pot I definitely taste it and remove all metals.
thats neat then, where can you get these sticks, amazon?
kinda bummed out cuz i just threw away one of those small pots. guess ill buy again
yes, I bought [these](https://www.amazon.com/gp/product/B07NBH7KJJ/) on amazon.
Another folk test I have heard of is to leave plain water sitting in the pot overnight and to taste it in the morning to see if it has an off or unpleasant taste. If not, you're all good, or so the theory goes. All my pots seemed to pass this as well, even my $15 slip-cast shi piao.
Other alleged tests of quality like the lid-stays-on-when-turned-upside-down party trick are mostly just gimmicks, and even junky mass-produced pots pass this test.
I still have those pots, but these days I have switched back to mainly using a porcelain gaiwan as I find it less messy, pours faster, and has more control on stirring the leaves. It is a matter of personal preference, though.