I try not to confuse these positive experiences with temporary fluency. That said: As a teenager I worked at Costco. Back then (early 90s) there was a job "front-end caller". Your job was to transfer things from one cart to the other, and call out the inventory number which the cashier would enter into the computer to ring up the item. Sounds like an awful job for a stutterer, but for some reason that job worked for me. I think it was the fast paced environment; you weren't thinking about the fact that you were talking, you were thinking about moving items from cart to cart, and calling out the numbers became rote. I might attribute this to the same effect as talking with others in unison or singing. But for whatever reason I was totally fluent while calling out numbers. And the funny thing is I felt at the time like fluency was a superpower. I loved going to work because I loved speaking fluently. Of course it didn't cure anything, I still stuttered and still do. But those 40 hours of fluency per week did wonders for me at the time.