i used to use soft craws but the onley luck i had were 5-10 pound channels

I have heard they even change colors through out the month in conjucntion with the phase of the moon.

Some people may not be familier with what is referred to as a
soft craw which I believe has to do with the moulting process when they shed the exo skeleton though someone correct me if I am wrong on this one

Crayfish also need to moult as they grow because their hard exoskeletons do not allow much room for expansion. Baby crayfish can moult on a daily basis but as they grow older, the regularity of moults decreases to a period of weeks or even months. The first few days after a moult, a crayfish's skin is very soft and it is very vulnerable to attacks from other animals and crayfish.

The early signs of moulting include lack of appetite and a slow down in activity. During this period the crayfish ingests calcium into an internal organ, not into the exoskeleton.

When the crayfish is ready to moult, it will try to find a hiding spot. Then it will move onto its back and begin fanning its pincers, legs and swimmerets (under the tail) in order to get as much oxygen as possible. The carapace will begin to crack behind the head; the new appendages then pierce the old shell; and then after about five minutes, a sudden, violent movement will detach the old shell from the crayfish [5].

The freshly moulted crayfish will invariably be larger as part of the growing process, but is vulnerable on several fronts. Firstly, the shell is very soft and vulnerable to predators, including other crayfish and fish. The crayfish needs to eat the old shell to replace the lost calcium and strengthen the weakened carapace.

yep they work real well for the channel cat, mostly for the lb range of 2lbs all the way up to as big as 20lbs i have caught them. and they do shed there outer shell 2 times a year around here. but some even shed the skin 3 times a year when i bring them home and throw them in a pot of boiling water to eat myself. when i fish for them i hook them threw the tail so as not to kill them and keep them the liveliest, but when i bring them home there there lunch.