I've just started reading Luama, Hayes, & Walser (2007) and from what I've read so far about experiencial control and acceptance, it sounds like you need to let go of idea that our experiences control our behaviors. This is the first step to a path of acceptance.
As it pertains to stuttering, I'll get personal here for a moment, I need to let go of the idea that I don't have to use some old techniques in personal discussion, but need to be fluent as hell when I talk in front of an audiance (e.g., teach a class, give a presentation, or talk in a lab group). It seems that for me, and possibly other people who stutter, this idea of being "hopeless", as Luama and crew call it, is being hopeless in the sense that we need to surrender the constant "fight" against stuttering and embrace it, but embrace it ALL parts of our lives and not just chosen ones. For it we are picking and choicing, it will creap into the areas that we think it won't dare enter.
We as stutterers tend to live in the past and dwell with a lot negative emotions on those past experiences. Anger, pain, depression, and frustrations are common foes and friends in our lives (they play the paradox of our existance, not much different than the paradox of "I want to talk, but I don't want to stutter.").
More as I keep learning ACT!