While Washing Machine can clean all the items shown above, you won't see every one in the Library's item list the first time you launch it. By default, Washing Machine shows only those items that belong to the latest version of the program being cleaned, and that aren't empty. But you can choose to see all items that Washing Machine can clean by changing an option in the program's preferences. Choose Washing Machine > Preferences…, or press Command-, . Click theGeneral icon; here's what you'll see:
The checkbox controls which items appear in the Library.
When you check Show empty items, you'll probably see that some icons in your item list have generic icons: that is, they don't look like the program icons in the Finder. For example:
The generic icon means that Washing Machine hasn't stored it in its own cache yet. To make the program faster, Washing Machine stores all the program icons it's seen in a cache of its own. To make Washing Machine display the current icons for all programs, choose Washing Machine > Empty Icon Cache. This will replace generic icons with correct icons for programs you have recently installed, and remove correct icons for programs you have removed.