Just my personal opinion and advice, I would not shop corporate commercial outlets for herbs, vitamins or any other stuff that's goin in my body. Not saying all they offer is tainted, but a lot of it is known to be (as pointed out by Hulda among others). This leaves you in the position of knowing how to determine good from bad among dozens or hundreds of products. You will likely have a much safer herb-purchasing-experience by buying - in person, from a well-stocked momNpop herb/health store. The safety factor quickly goes down hill when going corporate, whether it's corporate brickNmorter type or corporate on-line.
For Black-Walnut Tincture, depending where you are geographically, there may still be time for you to gather enough Black-Walnut s to make your own. It's not difficult and Hulda provides easy instructions (same ones I followed). I made a little over 1 gallon batch back in late August, was lucky to have found a tree with bunches of still-green walnuts to use for this purpose, collected about 1/2 bushel. Here in central Pennsylvania, most of the walnuts have fallend and do not have much green left on the hulls. You need to find walnuts that still have lots of green on them.
Another option - check the "Ask MH Barefoot Herbalist" forum here, he (Joel) is a Master Herbalist, he prepares by hand many of his own home-made herbal formulas and sells them the old fashioned way - by telephone order. He also takes email orders. He has a formula called "de wormer" that is based on BWH Tincture but also includes some other herbs blended in. YOu can find him here - http://www.108pages.com/
parasite Cleansing should be a regimen you continue for the rest of our life, and consists of two stages: introductory; maintenance. Introductory is where you first start taking some BWH Tincture, and Wormwood , and Cloves, gradually building up the daily amount and stay on this amount for up to 6 weeks, then you reach the maintenance phase where you only need to take these once a week. If you are planning to also do a Liver Flush, start preparation by getting the parasite Flush going, then start some colon cleansing, then start some Kidney cleansing, then this all culminates with the Liver flush. If you are not planning on doing a Liver Flush, the other three flushes are still a good thing to do.