If I had to guess, I'd say that the reason using an accent works is that it focuses the brain on saying something in a certain way instead of focusing on not messing the entire phrase with the stuttering. Cause, you know, the stuttering usually gets worse when you think about it. So I guess that just about anything that makes you focus on other aspects of the thing you're trying to say, other than the stutter, could probably lessen it? Like, singing? Should we all go living through life Disney style and spontaneously start singing on random moments? That'd be great and I think everyone would start paying a lot more attention on how to treat someone's stutter, even if only to stop the annoying spontaneous singing.