My speech therapist gave me worksheets to do. It was reading those worksheet sentences. Using the fluency that I have been taught. That last sentence doesn't really convey things properly. The same worksheet would be read differently depending on the stage of my progress towards fluency. In the car, I would apply those same approaches as I listened to the radio. Answering things the DJ or radio host said . Now, granted, I never stuttered when alone. The point was to practice my fluent speech. Going back to the piano analogy... Therapy sessions went one of two ways. Sometimes based on my progress, The therapist would move me along. Introducing a new element or modifying an existing part of the program. Other times the therapist might have me back up a couple steps in the progression to an earlier stage in the fluency program. A bit of course correction if you will... It was a layered approach.