Maybe curry and Showsheen the living *$%# out of him? Haha if he can handle it that is. I don't clip much but I know my old trainer would douse the poor critters in the stuff before she clipped them and the blades would cut through the fur like butter. She DID bathe them within a day or two before, however. The biggest concern if you're not fully bathing is dirt dulling the clippers.
Also a though-do you have a microwave there? You can soak a hand towel with water, microwave it until the water in it is nice and hot, and then scrub the dirt off with it. The warm water evaporates quickly so it won't chill him. Just make sure that it's not scalding hot, either!