You can lure them out with Live or Frozen Worms BUT with such a big tank mate if he did come out during the day, the Oscar might have a go.
Instead I'd add moonlights. Blue lighting won't disturb the fish and you can see your catfish.
Striped Raphael's are VERY Nocturnal.
You want to avoid a big fish trying to swallow a catfish with spines. It ends badly for both. I've seen it. http://animal-world.com/encyclo/fres...striperaph.php
I believe they are territorial cats. If you get a second, have lots of hiding places.