A great product to thoroughly clean an action or trigger assembly of dirt, oil, grease, cosmoline or anything else is Remington Rem Action Cleaner. Rem Action Cleaner is a powerful degreaser that will dissolve grease, oil, cosmoline, CLP or anything product from a metal surface. It cleans to the metal and with the aerosol propellant will blast dirt and other debris away as well. This is a great product to clean off preservatives like cosmoline from old military rifles that have been stored.
Rem Action Clear is a super powerful degreaser and caution should be used when using this cleaner. Use it outdoors only with good ventilation and protective gloves and clothing. Always read the Danger warning label on the can before using. Buy Remington Rem Action Cleaner from Amazon.com