I just thought I'd post these, as I find these to be very good tutorials on the use of the clinch for Muay Thai and MMA. This guy has a very good understanding of upper-body wrestling and controlling one's opponent to set up strikes.
The coach is an ex-fighter himself. If you search for Samir Seif, you can find a video of him being knocked out in the WCL. He seems to be an Erik Paulson type of guy, though. A very wide array of techniques and an expansive training background, along with very clear instruction. I'd love to work on clinching with this guy--neither of the Muay Thai schools I've trained at have worked on the clinch enough for my tastes. I'm sure this is just because Muay Thai in the west tends to be more kickboxing than real Muay Thai. Sigh.