Auriel, I advise getting a TENS machine and give it a try.
As for the herbal thing, I always advise that a person steer well clear of taking something that they get off the internet which is unregulated and basically unknown. You can't learn anything from reviews when it comes to this kind of thing and as Jay indicated, it is a huge gamble to just swallow something you don't even know about, nor know the real source of it , if the source is reliable or not, or what it really even is.
Don't gamble with your body this way, is my advice.
Now, if interested in this, what I would suggest is first look up and research all the info I can find on this herb...not from sites that are trying to sell you something, but from scientific botanical sites.
Then, I would go in person or call my local (or not so local) herb shop and ask them about it.
Or, ask a Naturopath what they think of it.
Then, if it seems like something worth trying, find out what dose is good for your size (again, a Naturopath or certified Herbalist) and then get it from a source you can be certain is reliable, such as a local shop or a company which comes highly recommended by a professional or someone you know. Anything else is a crap-shoot and I figure that I have enough problems with my body without doing experimentation with something which could be harmful.
Just reading reviews of something on a selling platform doesn't tell you what you need to know about something like this, since some or many of them could be fake. Etsy makes no investigation or regulation on what is sold as long as it is legal. And sometimes, I have found, they don't actually know what is illegal.
If the species in endangered, no one should be selling it, but that doesn't mean it is on the protected species list. Be worthwhile to look into that too, perhaps.
+ 
- so what!? (But don't!) Can't remember: tried a TENS unit on that? 
