I've been trying this out this week during the rare occasions where I remember about it... and I think it helps! I had a very impromptu meeting at work with two high-profile media representatives, and though it didn't go perfectly, went much better than I would normally anticipate these sort of unannounced meetings to go. The only thing is, I wish I didn't block, but had a repetition-based stutter instead. At least its doing something. Telling yourself "I'm gonna block the shit out of the next sentence! I'm gonna block so hard and so long that my head will explode!" seems harder.