If you run a search on google groups about this, there's a good deal of feedback on flushes. The most often recommended thing is Valve Medic. Warm up the engine, dump it in, drive around a bit, change the oil. Next time you start it up, angels will sing, rainbows will shoot out of your exhaust pipe and the engine will no longer rattle.
I've run Valve Medic through this engine twice in the past 3 months. There was very little singing, the engine still rattles and I keep forgetting to check for rainbows. This car has pretty low mileage for a 10-year old vehicle so it's been sitting around a lot. Naturally things are pretty gunked up. Other than the VM, i've been trying to take the moderate approach and just let it clear up on its own since now it gets driven to work every day. Also I manage to find an excuse to change the oil ever 1-1.5k.