Caustic soda (sodium hydroxide) is the functional ingredient in Easy Off oven cleaner. Using oven cleaner does not require heat. Simply place the part into a plastic bin (like a Tupperware container), spray the piece thoroughly with oven cleaner, and put the lid on. Remove after a few hours and wash thoroughly to remove any residue. Stuff works great, but is quite hazardous. This should be done outdoors. In addition, rubber gloves and eye protection are must-haves.
There are other, less-hazardous alternatives available. Castrol makes a cleaner that will remove paint very effectively. I've even used Pine-Sol to effectively remove chrome plating from styrene. These materials should be considered prior to using the Easy-Off method.
Gip Winecoff