Now that I've got the 3.6 with twin tip exhaust, I find they really get sooty and hard to clean. What has worked best for me so far is to use a (new by the way) toilet brush with the stiff bristles. Cleans it up nice with just soap and water. A little wax on the inside of the tips also makes it clean up easier the next washing. Anyone else as anal as me and whattaya do?? I guess the black soot is a common result of DI engines these days.