RE: "Funk" on the Muffler eewwwwwww
Also you do not need to "boil" it. Find a cheap crock pot, put it on the low setting overnight. Any real stubborn stuff can be helped along with an old toothbrush. I have cleaned many engines this way and it works great. If you boil the anti freeze, the high temperature tends discolor some types of aluminum and turn it dark. Use the low setting and the parts will come out looking like brand new.