kerosene is basically what sea-foam is...
as [MENTION=16454]slow90coupe[/MENTION] said, hit it with brake cleaner and a tooth brush. Use the old piston rings (cut one of them) to clean out the piston seats. once they are "clean" (you'll never get them like-new. lol) soak them in motor oil for a few hours. let them drip-dry before re-assembly. it will fill the pours of the metal with oil and help with initial start-up, but letting them drip-dry will make it so you can handle them during assembly without dropping them every 5 minutes. lol.
as [MENTION=16454]slow90coupe[/MENTION] said, hit it with brake cleaner and a tooth brush. Use the old piston rings (cut one of them) to clean out the piston seats. once they are "clean" (you'll never get them like-new. lol) soak them in motor oil for a few hours. let them drip-dry before re-assembly. it will fill the pours of the metal with oil and help with initial start-up, but letting them drip-dry will make it so you can handle them during assembly without dropping them every 5 minutes. lol.