I think the Essiac is really good for the liver. I have used it a number of times while off chemo. I use the Canacian alcohol based tincture also. Especially good while on the road.
Good luck with your alternatives. May we find something that helps us. Let's keep trying.
You can check the contents of "Medicine Man Tea" (use the ingredients on the ACS description of Essiac Tea: http://www.cancer.org/docroot/ETO/content/ETO_5_3X_Essiac_Tea.asp?sitearea=ETO )
If your goal is to boost the immune system, look towards Maitake D-Fraction (Grifron Pro version) instead. This is the *only* 'natural' immune booster that is in FDA approved Phase II trials (IND status) for breast and prostate cancer (although studies have shown it's activity in many other cancers; these were just the two most researched). www.maitake.com