That is how I like my catfish-clean and soapy tasting! Never heard of such a thing-should be an interesting story to hear if someone here has caught them this way. I'll try anything once-my pond has some that are 24" and most are around 18".
I know that this is a little late but,I just seen this.I live about a mile from pascagoula river(around vancleave,Ms)-I had traps in the past but,have caught catfish on this soap.
You cant just grab just any soap,on the ivory,it has to be original and when you buy the soap,squeeze the soap and make sure its not to hard.Some has been on the shelf to long and is to hard and will break and wont stay on the hook.the softer will.
At night fish on the bottom in a moving water where the fish can get a scent of the soap and the white soap will catch the eye..I first thought it was crazy at first but,I promise you it works good.In the slat boxes(traps)we used bait cheese.
With the rules and regulations now,its hard to just fresh water fish anymore.
I hope that this helps some.