Back when I used to catfish a lot, in my used to state, I would always use expired chicken livers or dead clams. Most grocery stores with a fresh seafood counter will either give you or drastically discount the dead clams. Just use some thread to wrap it onto your hook and you're good to go.
Catfish are also attracted to light. We used to take glow sticks and tie them to another pole with a heavy weight and throw it somewhat close to where are bait was sitting. I don't know if that would be allowed here in Washington or not.
