I have only used a few frozen baits. The effectiveness compared to fresh cut bait seems to have more to do with staying together rather than drawing in a catch. For example, a fresh dead bait, I think, holds the hook a bit better than a cigar minnow just thawed out and dropped overboard. I've used chicken livers for catfish, both fresh and frozen, however, with little difference. Frozen chicken in crab traps seem to work fine, but it is in a basket so staying on a hook isn't a problem. I don't know if it is real or perceived, but frozen shrimp do not seem to work as well as fresh shrimp. However, if I let those frozen shrimp thaw completely, actually get up to room temperature, maybe they too would stink enough to be just as good.