How did you find silent improve?

I thoroughly enjoyed the silent warm up, because it was something new and fresh. 
It helps the group focus and I personally thought it was a lot more fun than our usual warm-ups because we were not 100% sure on what we were doing but we still went for it and that was what made it so fun, just going with the flow.
Also with the silent warm up it was bit of challenge;
1: Because we had no clue on what we were meant to be doing
2: Because we usually chat for ages.
  

How can you use it in devising?

You could use this in devising to let off emotion without having to talk, which would be great for acting because obviously acting isn't all about voice, it's also about gestures and facial expressions...