cleaning oil out of headers?

So I fired my motor up again today, first without the headers and secondly with them on (plus my new V&H megaphone which sounds AWESOME). When I fired it with the headers on the oil residue inside the headers burns and smokes pretty badly. I was wondering how I could clean them out. Spray carb cleaner or another degreaser inside and then pressure wash out? Just keep running the motor until the oil is all burned off?

edit: just FYI, the motor is NOT spewing oil now... it's from before I rebuilt the motor

let it burn out

I was afraid you were gonna say that

run it down a backroad/highway for about an hour .youll clean it out and control misquito population! :laugh: