RE: " I do not see how an empty folder in a Widget that I downloaded and installed could be critical to operation of OS X."

-----------------------------------------

Well, actually, there are HIDDEN files even though a folder may "appear" to be empty. ONYX has a tool that will reveal any such hidden files.

In ONYX Preferences, go to: Parameters / Finder / Misc Options. Click the box marked "Show Hidden Files and Folders." TaDa. These magically appear throughout the entire system.

There are also other apps which can be toggled to serve a similar function: Invisible, to name just one.

http://www.northernspysoftware.com/software/invisible

If there are no hidden folders and files making a nuisance of themselves, then give SuperEmtpyTrash a try (as mentioned in an earlier post).

http://faqintosh.com/risorse/en/sys/setrash/