Yeah, folks gritch and moan about Google's lack of tranparency and guidance so much in this forum you would think that when Matt goes out of his way to give *specific* guidance people would listen.
Cutts doesn't specifically say that if you are Penguin affected (without message in WMT) that you should try disavowing links. However, I fail to see what else could possibly go wrong! I am getting next to no traffic from google. I have nothing to lose. I think he could be clearer though about the difference between Penguin affected without message and Penguin affected with message. As usual there is too much to read between the lines.