I just posted this in another thread, but I'll put it here too...
Use mineral spirits to put the metal parts in. It will clean off the cosmo pretty quickly. A toothbrush/toothpick will help get it out of those tight corners.
As for the stock, I used Simple Green and hot water to get most of the cosmo out. THEN I went back and used turpentine to clear it out some more. Applied it with 0000 steel wool as I didn't want to damage the stampings on the stock. Once it dried, I gave it a couple wipes with Simple Green again and one more with turpentine to ensure all cosmo was out. I then used Tom's 1/3 military wax on the stock (used it on my Garand too).
I rubbed in a heavy layer of Tom's mix (available at www.thegunstockdoctor.com
) by hand. Heat from my hand helped it soften and get absorbed. Let it sit for several hours (overnight is good). Wiped it down really good. Then applied another couple of layers with the 0000 steel wool to work it in better. Wipe and repeat until your stock is how you want it. I did this about 3 months ago on my rifles and I think they're thirsty enough that it is ready for another good coat and I'll be good for a while.
Here is how they came out:
Garand After (middle rifle)