Skin head, remove eyes, brain and big chunks of meat.

Put in a big pot on the fish cooker with a good amount of Dawn Platinum and get water to almost a boil and cut heat back.

Come by every 30min or so and check on it, pulling off what you can each time.

Change water when it has oil floating on it and repeat.

A scalpel and some dental picks come in handy to get in the little crevices. Pliers are good to pull all of the cartilage in the nose out.

I have never used peroxide but it will get them super white.
NEVER use bleach