Anderson got Chonan in the clinch twice, the first time Chonan powered out before it was on right. The second time Anderson had it on full and threw a knee. Chonan took the knee on his forearm and followed it down for a single leg takedown. Which btw is exactly what Fedor teaches in one of the videos of his MMA clinics (maybe Chonan was at one of the clinics

). I'm not sure if Fedor has ever had to do it in a fight, since he tends to throw as soon as the opponent gets in grappling range.
The clinch works great if your opponent doesn't want to go to the ground with you. The problem with it is that you have no way of keeping your opponent from just changing level and doing a takedown (with his hands covering his head) ... watch the Chonan-Anderson fight and the Franklin-Anderson fight and you'll see the difference, and why Chonan was able to turn Anderson's MT clinch to his advantage, while Franklin got killed by it. So, if you're better on the ground than your opponent, the MT clinch can be devastating. If your opponent is better on the ground than you, you're better off keeping your distance rather than going for the clinch.