I agree Meg, it is very important before using herbs to check with a health provider if one is using pharmaceutical drugs. Also herbs may not agree with all who use them which is why it is so important to listen to what your body is telling you.
Here is a discussion from the companion site to the many sites which sell Dr. Christopher formulas on the internet. This is a site where you may find out how to use herbs for different illnesses.
Here is the page which discusses the blood stream:
Blood Stream Formula
There are many important tips on these pages, outlining how to effectively use these formulas. It is important, as already mentioned, to make sure that the lower bowel is functioning properly and in fact to have taken herbs prior to using these to regulate that area of the body.
Here is a three day Dr. Christopher cleanse for the lower bowel:
Three Day Cleanse
This page deals with skin problems, but also with blood cleansing herbs:
Skin Problems
Some suggestions for parasites and worms. The herbal syrup mentioned here may be purchased from those selling Christopher herbs or many are on the iherb.com site at a good discount:
Parasites and Worms