Feels so good, I recommend it with lofty regards. You just need to figure out how its done, once you get the general idea experimenting is a lot of fun. I have managed to get at least 4 tones going at once, and you can really feel the balance of the forces in your throat. Clears it out really well too. I started by vibrating my lowest vocal chord (that I could fee at least, don't know if there's anymore down there) and built up. you can get meta harmonies where the tones clash at the top of your throat producing a high pitched whistle.