Dan- I have looked into it quite a bit and found that almost no one has done much to try for them. What i did find was people in Labrador had tried it with limited success. The atlantics seem to stream into teh rivers fast and shoot up. The lower pools are never very good where as with the pacific salmon they can be very good.
When tha cohos start to stage a the mouths of estuaries I throw a Kaufmanns spider at them in Chartuse. They seem to hit that pretty well.
If you could find a smalller estuary i think it would improve your chances as the estuaries for most of the big atlantic salmon rivers would seem too big to effectively fish.
Let us know if you find anything else.