Dave you should be in the authoring business, oh sweet residual income.

Immersion is the way to go for a proper clean. Unfortunately my first effort was a case of a little knowledge is a dangerous thing and went pear shaped, since then Dave has kindly put me right.
You need to be able to identify what your dealing with and the subtle differences in the way you treat different types of rug or you can come a cropper.
For the 'typical' UK carpet cleaner when their custy says 'can you just run over this' or even the more affluent client who gets their oriental from John Lewis. There is still huge resistance to the price point that makes immersion cleaning a goer, although there is the arguement that 'educating' the client is part of your job to get the price and that immersion can be relatively rapid once you have the right setup and can batch jobs together.
Dusty. I commend you on your defence of your book pricing policy, slightly let down however by giving it away free on your course. Nice web site.