If you have a go make sure you go to people who really know what they are doing. Acumedic mentioned here in Camden London are well known and supply practitioners with books, supplies, extra training etc.
http://www.independent.co.uk/life-s...ever-worked-against-the-ringing-a6942451.html
http://www.independent.co.uk/life-s...ever-worked-against-the-ringing-a6942451.html