A litany is a list. It's all words. It must be a collection of things that are said, or at least sayable, whether they get pronounced or not. A litany of complaints, a litany of excuses, a litany of desires, of goals, of new ideas -- all refer to words, or the ideas underlying words, as if they were spoken.
You can't have a litany of physical objects like chairs, or cars, or soups, or sporting goods, or anything that isn't potentially linguistic. You can have a litany, or list, of names for any of these, but not of the things themselves.
In the example sentence, one wouldn't use the word list for what he found, because he didn't find a list of objects -- he found the objects themselves. Similar remarks for litany.
- He found a list of bigger objects: a volleyball, a cathode-ray tube for a 19-inch TV, and a truck tire mounted on a steel rim.
- He found a litany of bigger objects: a volleyball, a cathode-ray tube for a 19-inch TV, and a truck tire mounted on a steel rim.