Nasty old food, rotten meat-things that you wouldn’t eat. I don’t blame you I wouldn’t eat it either, but it makes great catfish bait. Catfish love old, rotten, food. It’s a 5 course meal to them. A good example is, a few summers ago, I was catfishing at a local pond. The secret to that pond was that there was also a lot of easy-to-catch trout. So the cool thing was, I didn’t need to bring bait at all. Because I would catch a trout and slice it up into chunks with my pocket knife, (also making sure it was not still alive and suffering).
Next, I would put it out in the hot, colorado summer sun for an hour to ferment. After all of that it was the perfect bait. My homemade trout-bait caught me over 5 ten pound catfish in that one day. So my point is, if it smells bad, or tastes rancid, then good! It might just make good bait for catfish.