The ones I throw that do well: carrot, cabbage, potatoes, mushrooms, leaks, corn, eggs, several types of meat. When I was a student, I used to throw in cans of cream of mushroom etc, but I don't eat canned food anymore.

The ones I take out after boiling for a while: onions, bell peppers, meat bones.

Ones that are kinda okay: beans of various sort (become too soft, yet don't disintegrate fast enough, and collect at the bottom of pot so difficult to take out), cooked rice.

Definitely bad: noodles.

Anything you'd normally make a broth out of would be a great fit!

Including bones / carcasses.

Potatoes would disintegrate.