If possible try to get a box of whole squid. These are usually in either 3 or 5 pound sizes and contain the whole squid. I use these and find them to be a bit better then the pre-cut squid strips. You could also try fresh clams, just crush the shells and remove the clam for feeding. In my experience the squid will almost always ellicit a feeding response from most sharks. I would also suggest whole, fresh mackerel. The oil content is very high and mighty but the added scent may trigger a better feeding, be warned use sparingly as the oils from this fish can overwhelm most skimmers.