I would just go ahead and treat the bad cylinder as things are, Vernon. As long as the oil isn't too dirty, I'd just leave the oil it has now in place. For this treatment of the bad cylinder, you want a cold engine due to the aluminum cylinder head plug threads.
I'd order some more Snake Oil now, as it's on sale right now. At your discretion, though Snake Oil will give most of it's benefits to the complete engine in ONE treatment- if it were my car, I'd do another treatment w/ the 10 CC Snake Oil in the oil. And I'd like to do that right after an oil change to give max benefits.
I bet you will see an amazing improvement for this engine by treating the bad cylinder directly, then doing a repeat treatment with the 10 CC Snake Oil.
Once again, for benefit of everyone, here's a brief peek at the active ingredient in Snake Oil--Hexagonal Boron Nitride, hBN.
hBN reduces coefficient of friction by at least half.
hBN minimizes contact betwen friction surfaces.
hBN is a nano lubricant, is highly chemically stable.
hBN has high thermal conductivity, enhancing heat transfer away from friction spots.
hBN fills in micro crevices of wear surfaces, while coating hight spots with nano sheets of hBN.
hBN under load forms nano layers that orient in parallel with direction of sliding friction pairs.- the hBN molecular nano-layers have EXTREMELY little friction between them. hBN nano-sheet layers under load, aggregate with oil molecules. This then distributes uniformly over frictional contact areas, increasing separation of friction surfaces.
hBN has high corrosion resistance and resists oxidation up tp high temps.
hBN under light loads is absorbed physically and chemically on friction surfaces. Under higher loads hBN has a tribochecmical reaction which gives anti-wear performance.
hBN is used in several industries as a high-temp lubricant.
Let us all know of your results, Vernon!