A dichloroacetate is any salt of the dichloroacetic acid (DCA), usually sodium dichloroacetate. This class of chemical compounds have been making the news since 2007, when a study showed that they might be a cheap cure for cancer. The story has been slowly evolving since then, but there's still no valid clinical evidence that DCA is an effective cancer cure in humans. Science has not stood still, however, because DCA has been shown to be unsafe.
The usual conspiracy theory is that DCA cannot be patented, and lacking patent protection, Big Pharma would never conduct the required clinical trials. This is patently untrue (har har), because DCA has been in clinical trials since 1994. Second, there is an option to file a "use patent", which covers the use of a non-novel small molecule like DCA to medicate a certain disease. There has been some legitimate interest in DCA, because DCA can kill cancer cells in vitro, i.e in a sample of individual cells under a microscope. Then again, killing human cells with chemicals is not that hard; the hard part is not killing the whole human too in the process. As of August 2018, there are 20 completed or terminated clinical trials for DCA.
Before you start adding DCA to your morning cereal, be advised that DCA is still toxic, like other chemotherapic drugs. Pure dichloroacetic acid is corrosive, so it is usually administered as a sodium salt (sodium dichloroacetate). Even so, it is a metabolic poison that damages all types of cells, and damages the liver in high enough doses. The damage it causes to nerves (neuropathy) has forced even legitimate clinical trials to a halt. In nerve cells, it likes to strip off their protective myelin sheaths, which are necessary for their functioning. In high enough doses, it literally makes holes into your brain. Considering that clinical trials have found no clinical benefit with cancer, there's no good reason to subject patients to such toxicity.
As DCA is a relatively simple and easy to obtain, some cancer patients have started self-medicating. (Bad idea for a number of reasons, including the fact that it appears to be toxic in large doses.) A cottage industry of
enterpreneurs quacks has sprung up to supply them. At least one US website selling DCA to patients has been shut down by the FDA. There have also been fraudsters selling fake DCA. You might ask if that's more ethical than selling the real stuff, given that medically unsupervised ingestion of DCA is dangerous and potentially fatal.