I'll offer this, and I'll probably get flamed for it ...
Consider using some ARX to release the "varnish" slowly and carefully, rather than slamming it with a quick flush. First, soften it up and get it back into suspension in the fluid, then do a rinse. Follow the ARX directions.
This is one of the easiest and least cost methods to at least attempt some form of restoration to the formerly clean parts. Varnish is really only a big issue in the valve body; the gears and such are not really at risk. The risk is in getting debris stuck in a spool valve, etc.
The ARX is a product that works slowly and methodically.
Some folks have had poor results (little to no improvment) when using ARX. Somen like me, have had great results. It has always been my theory that the ARX works best on parts that move in relation to each other. IOW - ARX may not clean varnish off of a camshaft tower or connecting rod beam, because there really isn't any relative action against those parts. But the interaction of mechanical parts (piston rings, seals/shafts, shift valves, etc) is where it shines. I think of it similar to cleaning your hands. If you simply soak your hands is soapy water, it might release some dirt. But if you scrub with the soap, the soft abrasion lift the contaminants and suspends them in the soap. ARX, in my mind, works similarly. That's why some folks have great success and others do not; it's based upon the application and the expecation of what it's asked to do.
I'm not giving anyone an assurance that it will work. I'm only pointing out that slow cleaning is much safer than a hurried slam of several OCIs. And it's "cheap" compared to a rebuild. If it does not work, it's not like your out that much money in the grand scheme of things. And, when done correctly, it is complimentary to the OCI change procedure.
Food for fodder.
