I use either a large metal spoon too or a large offset spatula. I try to scale outside if possible. If not then I set in a large metal bowl in the sink for easier cleanup. As a chef in a restaurant I've used the same. I don't like to use knives or those toothy scalers - I don't think they do as good a job. The fine dining restaurants I've worked in receive whole fish that need to be scaled. I'm sure there are others that only use processed fish.
BTW it's a universal truth that if you scale, not matter how careful you are, no matter how well you clean, you will still found scales stuck in the most surprising places.
Scaling and de-sliming are best done in two steps. Concentrate on scaling cleanly first and then de-slime with either an offset spat or a knife. For those who don't know that procedure it's just like the squeegeeing the fish.
Where did you catch that fish? The Kings and Cohos I caught off Alaska had gently concaved tails, not forked. The Cohos/Silvers are also very different because they really put up a fight - jumping out of the water, running out the line, etc. - while you're trying to reel them in.
JasonM and imsscott, I think Jay K wants to eat the skin, yes? I always do - sometimes only the skin - though I know a lot of fisherpeople don't.
Here's the first King I caught this summer off Sitka, Alaska, where I was working as the chef for a fishing boat and lodge. It weighed in around 25 pounds.