This is a moot point for me, since unless or until I learn German I wouldn't be able to read such a book except in translation, but I wonder how many Swiss novels use Swiss-German in dialogue, in the way English-language writers will imitate accents and dialects (as opposed to "proper" English) to show how people actually talk. There are many examples of this, but the most obvious one I can think of is Mark Twain's The Adventures of Huckleberry Finn.

Of course if there isn't, are there any Swiss books (hopefully translated) that anybody would like to recommend? Thanks!