yes you can catch channel cats all day if you go under boat docks or under the big rocks they use to line the damns of smaller lakes. they are fun but hard to catch because they bite and run. this is a fun thing to do with people who have never done it before. the booom sound a catfish makes under water is scarier for more people than the fish itself. talk about fun but in oklahoma at least you can only keep flatheads to be legal.
as far as the blues bitting hard yes they can bite verrrrrry hard. much harder than flatheads. i think it has to do with the muscles on their heads where flatheads don't have as much, its mostly just bone. with a blue, they will sometimes bite and squeeze your hand or foot or whatever goes in the hole first. i sometimes stick my foot in the bank of a river first, if the hole goes towards the surface it can be a beaver hole. never been bit by a beaver, don't want that story to tell. but i have felt many.
i have taken buddies with me so they could try it, and it has been the best memories. we laugh about it over some cold beers later. its even better if you use scuba goggles because you get to see their reaction when they are bit. i damn near drown last year laughing before i reached the surface.
as far as the big blues drowning someone. i think it is the lack of experience that causes the danger not the fish. usually someone goes into a river bank and they get hung or even when noodling those rocks i mentioned, you have to be careful not to stick you hand in a place you can't pull it out of. i learned along time ago with blues they will turn you loose after about 10 seconds if you remain still. then you can come up and get a better breath and go back and get after it again. with a flat head they never just bite and squeeze, you have to react and grab them when they bite you or they will go way back in the bank if the hole is deep enough and sometimes you can't reach them. i never recommend going alone because you can drown in the most shallow water if your hand is caught in a rock. its more fun with buddies anyway. in oklahoma i believe they stocked the blue cats in the 1940's but i'm not for sure. anyway the biggest we have cought is 66 lbs. it was huge buy manageable. i think these big fish stop breeding after they get so old, i'm not sure but everything else does so i don't see why these fish wouldn't be the same. there have been a few caught over 100lbs on jug lines but none noodled that i have heard of. just a guess since i haven't caught many over 50lbs.
catfish start nesting pretty good after may 15th so i want to hear some stories. if i get some rain i will try to figure out how to send a picture on this thing.
