I've stuttered my whole life, and I know the anger I can feel at myself when I sound like a forgetful rambler in presentations, and have to gain pity smiles from people at school, at stores, any where. I'm also a 16M. Speech therapy never helped me because they don't understand the problem. Reading words of a children's book doesn't do anything. Stutterers can mostly read that just fine. Stuttering is that we can't freestyle talk without stuttering on our words. I have talked to myself outloud as a natural habit, completely unrelated to my stutter, for my whole life. That is my practice. And it has helped me go from being unable to even start a word to at least being able to hold a conversation. Stuttering isn't illiteracy. When a soccer player practices for a top-level match, he doesn't practice how to not kick the ball with his toe, he trains intensively with the team. It is simply simulation. Talking to yourself is a simulation of talking to someone else, that someone else being your conscious. It will definitely not make you completely fluent, but it certainly helps A-LOT, because you know how to speak freestyle because of it without stuttering. It is literally practice.