I tried something new today, and it looks like it might have worked. We’ll find out for sure in a week or 2 when I finally get around to coating the thing.
I picked up a used valve cover for my 240z in a junkyard several months back. As we know, its next to impossible to clean under the baffling. I turned the thing upside down with the oil cap installed, plugged the pcv neck and filled with about 75% simple green/25% water.
Put it in the oven and got it to almost a boil for about 2 hours and drained it. I can’t tell about under the baffle, but there is no more caked on oil and grease on the exposed parts.