Noodling is sticking your hand in a hole and wiggling your fingers as bait. The catfish chomps down on your arm and you rip it out of the water. I've seen it on TV.. I'd probably do it if I were with experienced noodlers. But I prefer to get my catfish from Tony's Seafood. Catfish isn't all that expensive..
I know some people that go "noodling". I for one consider them crazy, but they swear by it. They have culverts set out in their private pond/lake for just this.
People don't fish as a means of saving money. I keep very little of what I catch and give 90% of it away.
Main reason you people noodle is a chance at a nice flathead. You can catch them with rod and reel or trotlining, but you got a chance at a big female noodling.