I read all of of the replies, and was surprised that nobody mentioned mechanics solvent, also known as cleaning solvent or as stoddard solvent. You can get it in 5 gallon cans at most real auto parts stores, maybe not at some of the chain stores ! You really have to work to set fire to it and it works almost as well as gasoline. I used it for many years on auto parts in my shop! Ed

I just did an SKS last month and found a can of gunscrubber to do the trick very well.

Us ol' soldiers always used GASOLINE to remove cosmoline, and this job was always done outside when there was at least a nice breeze blowing! Of course, since these were military weapons, we weren't particularly concerned that the gas would damage the appearance of the wood, since a couple of coats of linseed oil always went onto the wood after the cosmoline was off.

Over 50 years ago I spent many an enjoyable hour putting that cosmoline on and now guys are asking how to get it off! (I didn't do the Mausers though. That must have been Fritz).

I've used GUNK, the automotive parts cleaning solvent. Soak for awhile and it melts away.
Bob

Nope. The gasoline we used 50 years ago was plain old gasoline. Straight from the motor pool. We did it outside and the smoking lamp was definitly out. We used a 5 gallon mop bucket and put about a gallon or so in it. Then we stuck one end of the rifle in the bucket and started dipping and brushing from the top with a 2" paint brush. It was hard on your hands but, hell, we were bullet proof back then.

kerosene works great!