I used to block and force words that didn't come out. I still do it naturally (because that's how I used to "manage" my stuttering), but I'm working with my speech therapist to let it come, without trying to hide it or fight against it. And I have to say that letting it come naturally is so much more enjoyable, and you no longer have (or less and that's already something), this feeling of helplessness and tension. So thanks to my speech therapist my goal is not (anymore) to be fluent (it is practically impossible, even if techniques can help greatly), but to accept to let my stutter out.