I didn't see this mentioned - I did go through the thread - there is a simple technique to get a lot of the valve train deposits out quickly. Then the cleaning oil can work much, much bettter.
Since you have the valve covers off, (?) use a very high quality brush and just "paint" the valve train with warm kerosene or even diesel fuel. You will be surprised how fast it will dissolve that. It will run down the oil journals, cleaning them, too. Do this with the drain plug out. Once it's clean, plug it and fill it with cheap oil, run it briefly to further remove any remaining fuel oil or loose particle (a quick rinse basically). Change the filter oil and put in your 0w-40 or other ester oil, and then do your OCI's as you wish. This is a time-tested, cheap, effective technique.