Hi,
The removable baffles can be best cleaned by putting them in a wood fire that is burning clean. They don't need to be too hot, just hot enough to burn off the oil coke. You will need to wire-brush and oil them afterwards.
However, the whole pipes will have a fair amount of carbon/coke in them. The only real way to remove that is a warm soak in Lye (caustic soda) at about 1lb caustic crystals to 1pt water. Heating it and keeping it at about 80*F will do the job in about a week. I do them cool without heating about 50*F and it takes a month. You have to circulate the solution inside about every few days. This is what Chrome platers do to strip/clean items before plating, they hate 2T pipes because they spoil their hot Lye bath with all the crap that comes out. Some members have made their own hot baths with large dia plastic pipe and thermostat controlled immersion heater.
Beware, Lye (caustic soda) is deadly and dangerous. You must read it up before using and it is dangerous to everything, so don't do it where it can hurt/damage anything, like things,people,children,pets animals etc.
So, have a think about that and read it up. BTW, It is safe with Chrome and Steel.
5port