I read on Earthclinic about brushing the tongue with salt but decided to try something less irritating instead. Plain baking soda works! I bought a tongue brush at the pharmacy (a little rake-shaped toothbrush for the tongue), dipped it into a bit of baking soda which you can buy at any supermarket, and just gently scraped my tongue with it. I scrape and rinse the brush, scrape and rinse again, and add more baking soda if I need to. Tastes pretty bad and makes me gag sometimes, especially when trying to brush the back of my tongue, but after rinsing it all away, my tongue is a healthy pale pink colour. ALL of the white is gone. I have to repeat every few days because the white coating comes back but it really helps! My mouth always feels fresh and very healthy for a couple of days afterwards and then I repeat again when I see signs of the white coating coming back. Works every time.