I've hit summers on periwinkles and nightcrawlers (about half inch of the tail threaded on the hook behind a size 14 mettalic red corkie). Another odd ball bait you might try are meal worms. I use these odd balls when I know fish are sitting in the hole, but have been pounded into not opening their mouths.

If you're dealing with fresh fish, you can't beat your basic sandshrimp for summer runs. In my experience, I've found shrimp work better early in the run (May-July), and eggs work later (October). Bring both though, I was on the Kalama once in May, and bunch of hatchery fish were pounding on eggs and completely ignored shrimp (I had the shrimp). Also hear eggs outperform shrimp on the Cowlitz (is this a Columbia basin thing?).

Like the 500 corkies you carry in your vest, I guess variety is the key.