I'd avoid anyplace around Shilshole for crab and head north. All the beaches in King County are closed to clamming due to pollution, so if the filter feeders are tainted, I'd think the scavengers would be as well.

Try the launch at Camano Island State Park. It's about an hour and twenty minutes from Seattle, no ferry required. You can drop pots and then troll for silvers.

Delbert