I've tried all sorts of off-cuts & tinned sardines in my lobster/crab post but the bait which caught lobster was wrasse (offcuts of large ballan wrasse, used in Bouillabaisse). I've also seen a professional potter using wrasse, among other off-cuts. Kind of makes sense, wrasse are prolific in the rocky areas close to shore where lobster tend to be, as their skin has a distinctive "pepperiness", at least that's how it seems to me.
One of the SA forum members suggested limpets - again, found on the rocky shore where you tend to find lobsters. Although I suspect anything oily/fishy/meaty/manky could do the job.
I agree with you 100%, laying down a bit of bait such as a fish is a good way of luring lobster and crab out. I couldn't believe how successful it was when I tried it however I havn't had the chance to try it again.
I have a sore head to nurse today so I'm not going to think about it for the moment:friday.