Joe,
Do you use a whole sea robin in your traps or do you cut them in 1/2?
I throw the whole thing in, if it is a larger specimen (16-18") I will cut the tail off so it fits. I do score the skin a few times to allow the juices to flow.
If I need a quick fix though, a crab right away for the killie pot, I will use a piece of cut bunker on a hand line around the pillings. Have not tried sea robin for this yet.