FeedGhost provides facilities for searching the contents of the articles in your subscriptions. Simply click the "Search" button and the search tab will appear.
Enter your keywords in the search box and press enter.
Note that results may not appear immediately. FeedGhost builds an index for searching, and if many articles have been downloaded recently the index may not be up-to-date. Indexing occurs in the background when the computer is idle; if the index isn't up-to-date and you need it to be, just let go of the mouse and the index will built. The animation to the right of the search box spins when the index is being updated.
Also note that FeedGhost automatically archives deleted articles, so even if you choose to clean up deleted articles from the news list, you will still be able to find them via search.
FeedGhost can help you weed out feeds that are no longer available, or that haven't been updated for a while and are effectively finished. Click the "Problems" button to display this tab.
The information in the problems tab is divided into two parts: the top half shows those feeds that cannot be contacted, and the bottom half shows those that haven't been posted to in a while.
You can click on the items in the list for more information, or right-click to refresh, delete, or find amongst your subscriptions.
Of course, you need to use your judgement whether to prune the feeds listed: feeds that cannot be contacted might just be temporarily down, and feeds that haven't been updated for a while might have moved, or might just be low-traffic.