Free: Contests & Raffles.
A bucket of clean ocean water and they will live until the next day. I also hate cleaning them. Hate it. Not a fan of twin harbors I've had much better luck elsewhere, if you go there go near grayland, not Westport.
If you like casinos I'd suggest quinalt casino. There's great digging right out front, you can camp there or get a room in the casino.
I second the Quinalt Casino. We've been slaying them out there the last few digs. There's a few good threads/youtube videos about cleaning them. I cut a "C" to get the guts out, snip the neck and filet the rest of it. Egg wash and some Pregresso Garlic/Herb bread crumbs and it's a home rum.