To be able to get out of your comfort zone, even a little is a huge success. There are people who are staying inside their confort zone for years. It is big inspriation for me and for many others. What if continuing to talk when you know you'll have a blocker won't make you anxious. Wouldn't it be great? One experiment can be that everytime when you have an anticipation of stuttering just do it eventhough you will feel anxious and it will cause more stuttering. Eventually your brain will know that you won't hold yourself back in such situations and it will get used to it and it won't cause more anxiety.