That's because Dawn has a special grease-fighting formula in it. I've used it on other non-dish items, and it works like a charm. In fact, I've used a mild dish soap solution to clean the carpeted car mats from my '98 New Beetle and my '05 B5, and they came really clean. You let them air-dry a while, and you're good to go. Saves money that way, too. Dish soap's far cheaper - does the job for a fraction of the cost of other cleaning products. And it doesn't leave your interior smelling like a French cathouse like some of those perfumed carpet cleaners do! I used one such cleaner in my Bug, and for several months afterward, I had to put various air fresheners in the car to kill the sickly-sweet, almost nauseating stench.Just cleaned mine last night, and used Dawn (the dish washing soap), and cleaned them no problems.