The mouth of a catfish is like super rough sand paper. you get to lippin and bunch of them and you will end up bleedin. The barbs on them little ones are sharp. I guess they hadn't wore them down from wiggling back into spawning holes like the big ones do.

Circle hooks work great, no need to set the hook. Be mindful of how much bait you gob onto them though. You really need the point exposed and not buried down in a shad chunk or something. I like Owner and gamakatsu hooks. One is Mutu light circle hook, I don't remember which brand but they are very sharp and just aobu the right size for eating size catfish.