I'll go along with the 'why worry about it' and use Dawn Power dissolver comments. I will take off a muffler now and then and clean it just for aesthetic purposes but normally I leave the engine alone until the time comes to take it out for some reason then I clean it with Dawn, a scotchbrite pad, oil it up and ready to go again. And I like some cstor in my fuel but I don't want to start that battle again!