I'll take myself as an example. I have blocks. There was one point in my life that I used repetition of the words before the block as a successful way to work through the block. Eventually the brain adapts to this and what I am left with is a more complex stutter. Not only do I have blocks but I have this compulsion to repeat the phrase before the block as well... and it doesnt help anything. I have been trying to reduce this behavior for years. Its challenging. It all stems from fear of the stuttering moment and we do these secondary behaviors to try to prevent the stuttering moment from happening. Truth is, letting the the stuttering moment happen is usually a more simple experience and if you ever record yourself, its actually more pleasing for the listener, as oppose to having finger taps, tounge clicks, phrase repetitions, etc thrown in there as well.