[DSPTurtle]

I had good luck using a bottle of techron poured into a dish with a toothbrush. Then followed up with carb cleaner and a little brake cleaner for good measure.
As for the portion of the cylinder at the top where the rings do not come all the way up... I used a green scrubbie, simple green, dish soap, elbow grease, brake cleaner, more elbow grease and another green scrubbie. Took awhile but once you get it started it tends to come off much more quickly.