I am a natural health researcher and author, In my opinion, Hulda Clark has some great cleanses and de-tox programs and some very good advice. On the other hand, I am less than totally impressed with her zapper and I think she is totally off base with her claims about mysterious flukes being the cause of all cancer and disease.
The best supplement I know of for most cancers, and especially brain cancer, is oleander extract (with the toxins removed) - which is available as a patented medicine as well as an herbal supplement. It is a tremendous immune booster, induces cancer cell death via both apoptosis and autophagy and also crosses the blood brain barrier.
Another good one is inositol/IP6, which has been very successful in reducing and eliminating tumors.
For more information about oleander, I recommend you read "The Oleander Series" of articles at:
http://www.tbyil.com/articles.htm
You can also find a very effective (over 90% by my reckoning and experience) natural anti cancer protocol there, as well as at:
http://www.naturalnews.com/022808.html