I can't imagine there are many things you could do with a cock and a rope, other than tie it up. No wonder you're looking for new ideas. What have you tried so far?
Perhaps work on some new knotting skills? Or tie one end of the rope to the refrigerator and offer a beverage to your guests?
What I do is cock & ball rope bondage and then use the "leash" end I've left on the rope to pull his balls into easier access for torturing with various things.