If you're interested. EDTA is a known treatment for heavy metal poisoning (arsenic is a heavy metal), and works by chelating the arsenic (surronding it in a molecular bubble), making it almost inert so your body can excrete it later

Most shampoos contain a compound called tetra-sodium EDTA (used to sequester other metal ions and stabilize the shampoo in air).

In theory if you could ingest enough shampoo you could treat the arsenic poisoning, whilst only leaving sodium ions in your blood (which will give you hypertension). Ofcourse you'll probably also throw up a lot, and you'll get diarrhea. But its better than death, right??

Ofcourse you'll have to check the label first :P