I think speaking to others without stuttering 10 hours a day will be likely to have way more positive effects on your stuttering. But according to Cognitive Science, different situations/occasions will remodel your neuros differently and that's why speech therapists are all the time inspiring you to use speech techniques in real conversations but not only in talking to yourself. Plus, stutter is not caused from lack of practices of speaking but different neurology. The reason that you are reasoning will cause other disorders like aphasia.