cleaning gunk out of crankcase/head

I picked up a replacement head for my M50 today. The guy had it on a shelf for like 5-6 years. Prior to that it had been decked, checked for cracks, dipped, valves lapped, new valve seals, etc. After getting it back he had too many projects and ended up parting out the car and never rebuilt the engine. Put the head on a shelf and either he or the machine shop slopped some stuff on all the steel parts (bolts, valve springs) which he said was to keep them from rusting.  I assume it's Cosmolene or something like that. 

Fast forward 5-6 years....nothing is rusted at all, and otherwise the head looks great. But whatever stuff they put on there, which could probably just be rinsed off at the time, has now more or less hardened into a fairly solid gel. The PO (an old-timer) casually said "it'll come off with Acetone." And yes, acetone takes it off. However, it's in a lot of hard-to-get-to nooks of the head so manual cleaning is going to be extremely time-consuming.

Some pics:

third pic is after I put some acetone on it to soften it up, that's why it looks wet. 

In any case, what's the best way of cleaning this stuff -

- Just douse a ton of acetone on there and get as much as possible with Q-tips or whatever, and then rinse it with water (powerwasher?)

- Some other solvent

- Obviously could take it to a shop and have it dipped, but probably requires taking off the valves/seals/etc....and I'd greatly prefer NOT to have to deal with that hassle. 

- Get any loose bits out and just run it? Since it's a dissolvable goop, would it just "melt away" as the engine runs, or with some kind of crankcase clearner in the oil for a hundred miles or whatever?

Anyhow, any advice is appreciated. Would like to get this engine back together in the next day or two (competition coming up), but this is a bit of a roadblock that I'm unsure of how to approach. 

My impression is that a lot of machine shop parts washers use hot water and detergent these days, rather than a ton of solvent.  If so then it might be safe for the seals?

Big pot of boiling water is where I'd start. 

A quart of lacquer thinner in a paint gun will do wonders.

Mineral spirits gently cleans cosmoline from guns, its what i typically used. 

well, sometimes the easiest way is easiest. Because I'm impatient, and water isn't going to hurt anything....I spritzed mineral spirits all over it, let it sit for a couple minutes, and then blasted it all with my powerwasher. Then spent 15 mins with my air gun/compressor at 100psi and blew out all the water and any remaining pieces. Whatever the stuff is, it pretty much came right off using a 0-degree spray. I think I got 95% of it off of everything, had to use a pick for a few small pieces stuck between springs. In any case, whatever this stuff is it seems pretty soluable so i'm not too concerned if there are a few little pieces still around. I'll change the oil pretty quick after I put the engine together. Here's the "after"

Parts drying tip:  Rinse it off with the hottest water you can get, thoroughly, to make the part itself hot.  When you use air to blow it dry, don't blow it DRY dry, just blow off the majority of the wet.  If you use too much air you cool the part, you want to residual heat to finish the drying process.

The parts washer at the machine shop used a 180F solution of water and some expensive stuff from Zep.  Personal experience says the cheapest powdered laundry detergent works great for the home shop, in a wash basin/stationary tub (whatever you regionally call it) full of hot water.

For extra points, do this in August, manually scrubbing engine parts for a couple hours over a tub full of the hottest water the water heater can be provoked into making.

Pete. (l33t FS) said:

For extra points, do this in August, manually scrubbing engine parts for a couple hours over a tub full of the hottest water the water heater can be provoked into making.

lol

You can also put it in the oven at like 150 degrees for 30 minutes to dry it.