Whew! I'm glad I inspired you to do something positive!!
Giggle!
I'm not real sure why she wanted me to use the cut leaf instead of the powders - other than she didn't have me use any powders really. She believed in the 'whole herb' being used mostly. She's moved out of state, so I can't even ask her!
I've noticed that many people react differently on the different "forms" of Houttuynia as well and thought it odd. Some differences can be expected, but nothing like what I've seen over the years, which is why I choose to always clarify what type I used.
As for discarding the herb after only 10 minutes of steeping, she told me that it would be much too strong if it went any longer is all I know. After having herxed like I did for 3 straight weeks when starting it, I believed her, since it kicked my rear!!! LOL!
As for your observations in the variety in the quality and power/properties of the various herbs, I would agree as well. That's why it's best to stick with those companies that have a good reputation and/or you've had good success with. On Buhner's site, he gives herb company recommendations and you can always ask here for personal recommendations from the members to get you started if you need.