Very nice fish thanks for the time it took to make this report. As far as cleaning them you will find that they can be filleted and then tossed into a little vinegar and milk for a few hours and they are good to go. All of the soaking is not needed they do not have a mud line it is actually the main artery of the fish and it is edible, just a little strong to some peoples taste. I harvest many catfish a year and the 3 to 5 lbers are by far the best ones to cook. The fish at that size are less than 2 years old and they have not absorbed the amount of toxins that the larger ones have. You can fry them in chunks or broil them the flesh is very firm and light tasting. Remember that the catfish is a predator and given it's choice they have the same diet that Crappie and Perch do so the flavor is really close to being the same.
Art