"And it's so easy to do: just don't let a sentence through unless it's the way you'd say it to a friend."

Well no, it is very hard to write a text in "spoken language". This has been analysed by many writers, and the master of this operation in French language is Céline. He says that a lot of minute tweaking is required in order to produce the effect of spoken language in the reader's mind.

And this has not very much to do with removing the "litterature" from one's script, which is obviously much easier.