I don't think putting your stock in the oven is a great idea.
A 91/30 stock is about a week and a half long, and likely
won't fit in your oven. Then there's the dripping cosmo
all over the cookies Mrs.MosinMan is baking.
A hair dryer and paper towels will work nicely.
A water-proof, well insulated glove will help cleaning all
the metal parts. Remove the bolt from the action, and the
action from the stock. Point the barrel into your tub.
Pour boiling water from your kettle
into the chamber and down the barrel.
The heat will loosen the cosmoline, and the water will wash
it out. Several kettle-fulls,and let dry, it only takes a minute,
then run some patches liberally
soaked in Ed's Red through the bore. The recipe for Ed's Red
can be found here:
http://www.frfrogspad.com/homemade.htm.
Put it all back together and go shoot it. Shoot it lots.
The boiling water trick only takes a few minutes and will
also clean out all the salts from shooting corrosive surplus ammo.
Have fun!