I first heard about this product on Anthony Ross's podcast "Feed My Mind" as one of his guests was talking about the health benefits. I have done some more research and thought that there is no harm trying it out.
Get ready for a weird sensation! It feels very funny and there is a bit of technique involved to make sure you scratch your entire tongue. It's certainly gross when you see what you scrape off, but then again... It's better than leaving it in your mouth!
Keep the handles clean otherwise they might generate a bit of mould build up in your bathroom. Other than that get happy scraping!!