2.5 was stored for several years using cartor oil-trouble!

[d&smach]

The title shoud have read CASTOR oil, I wasn't able to edit the title. I have four 2.5's that sat for a few years after using castor oil. They were very hard to turn over and a good shot of wd-40 in the cylinders enabled three of them to fire up. Before starting the compression was horribly uneven from 45 psi to 165 in various cylinders. All of the first three after starting and running for several minutes to full warm up came back beautifully. very high and even compression in all cylinders. The trouble is the fourth one is sparking good and the fresh fuel is squirting nicely out of all injectors, but it turns over slowly (with compression from 35 to 165, most of them on the low side). My question is what can I pour into each cylinder while the piston is near tdc and the engine is tipped with plugs straight up to dissolve the castor oil that has the rings stuck? I'm considering a shot of methanol alcohol and give it a day or so to work before removing it and moving to the next cyl. Any other advice?