Black salve, properly formulated with no acids, just with bloodroot, sheep sorrel, gangalal, and red clover WORKS!
I have very sensitive skin and scar from everything. Tried this on a patch of the sensitive skin on my inner forearm. No reaction other than discoloration after 24 hour application. Had an abnormal mole the doc said was most likely cancerous. Put the stuff on that and WOW! Immediate reaction. After pain for days, the body pushed out the entire mole and its roots. Biopsy on my arm confirmed clear of cancer after that.
My mastiff was diagnosed with cancer on his elbow 2016. Put some on my dog that had a cancerous tumor on his elbow. Took a lot longer to treat because the bandage would not stay put. The tumor drained and then fell out. He should have died in a year or less. It is now 2020 and he is doing fine. The idiots that claim black salve is a hoax and dangerous are the idiots who are toting the pharmaceutical industry's nonsense. There are bad batches out there that put acid in their mix. Do not buy from them. Research and find a reputable company to get the good stuff.
The bloodroot ruptures the protective sheath around the cancer so the body can recognize it as bad. The body then appropriately attacks the cancer and shoves it out. There is a crater at first. Keep it clean, moist, and covered. Use a comfrey based salve on it. It will fill in, heal, and have little scarring if you follow the directions.