I have not read the book mentioned in the op, but I tend to use a somewhat similar technique to declutter my mind. When focusing on a particular problem, or topic I tend to scribble (or doodle) in my notebook without any constraints.
Once I have a good enough start point, I try and write down my thoughts in an email to (a possibly imaginary) a colleague who may be interested in what I have to say. The very fact that I now have an audience acts like a filter and helps me get to the crux of my idea very quickly. Writing for an audience also makes you evaluate what ideas may be relevant and what irrelevant.
Its even better if you have somebody you can use as a soundboard to talk about your ideas. Of course, thats not always possible (and is very obnoxious!), so the email method works better for me.
Once I have a good enough start point, I try and write down my thoughts in an email to (a possibly imaginary) a colleague who may be interested in what I have to say. The very fact that I now have an audience acts like a filter and helps me get to the crux of my idea very quickly. Writing for an audience also makes you evaluate what ideas may be relevant and what irrelevant.
Its even better if you have somebody you can use as a soundboard to talk about your ideas. Of course, thats not always possible (and is very obnoxious!), so the email method works better for me.