Couldn't have said it better myself. The process of doing this is called "overkilling". I do it on any word/ any sounds I find tricky or that I'm likely to avoid. It's one of THE BEST ways to become more confident as a person who stutters and eventually just a more confident speaker. The best ways of doing it is by using the phone, calling up hotels, and practicing feared words and sounds so that you can make those words become "boring" to say. Or make them become words in which you don't think twice about. The more negative situations you have trying to say a word, as you said, the more you're going to have trouble with it. Reserve the process and I promise anyone that you can get really good results.