People used to use barberry and now many prefer Oregon grape root. It is substituted using time honored principles, including the tenet that Nature is generous and provides many alternatives. There are at least 2500 herbs that have been found useful in treating cancer. Historically, some people added potassium iodide to the herbal formula. Recently, people have used Irish moss, alfalfa, or recommended supplemental amounts of something like Lugol Solution.
Some herbalists use fresh herbs that are organically grown or wildcrafted.
My own experience with these products is that they are superior. To tell you how serious the quality control issues are, I will relate a true but uncomfortable story from my Clinic days. We had a fairly good size herbal pharmacy, called Mountain Medicines. We dated everything we received and rolled over the bulk herbs every few months. In effect, the larger the producer, the greater the risk that the herbs will be second or third quality, even adulterated as with the hugely popular St. John's Wort.