I just found this thread again. Yes, the dashes are very common with native speakers. But using hyphens is not quite correct.
- hyphen
-- dash (two or three times as long).
That's true, but it's very common to use a hyphen for a dash in places such as this, given that computers don't have a dash key. In fact, what you've written isn't a dash; it's two successive hyphens.
I used to say that two hyphens were necessary to make a dash - in fact I've made the same claim here, I think, a few years ago - but I was persuaded otherwise.
The main difference between a dash and a hyphen is that hyphens cannot be separated by spaces. This is a hyphenated-word. This is dash - there is a difference. They can't be confused, because of the spacing.
I do use proper dashes in printed materials and academic assignments and articles (though I'd never try to pass off two successive hyphens as a dash in that context, especially if I were arguing that hyphens aren't dashes.)