The clinch is a misunderstood position/technique by the casual MMA fan. When they see this happen(the clinch) in an MMA fight they usually start booing or they might believe nothing substantial is happening. That might be true some of the time, but most of the time the fighters are trying to gain an advantage. Randy Couture and Dan Henderson are known for using the clinch to their advantage and being very successful with it. A few months ago, Couture at 46 years old was able to contain the much younger Brandon Vera and pull out a victory by dominating the clinch position and not allowing Vera to use his Muay Thai striking ability. Here is a video of Dan Henderson going over the basics of the clinch technique/position.
Here is a highlight video of Dan Henderson using the clinch, and the threat of clinching to his advantage. Check it out! Plenty of chingasos as well.