File Pruning Tool

I would LOVE LOVE LOVE some type of file pruning tool. There are no third-party add-ons that do this. What we need is the ability to parse through all the entries and categories and look for all files that are used (in dedicated file fields, grid file fields, and text/content fields) and compare that with the files that are in those upload directories and provide a way to remove the files that are no longer used/linked to. The tool could create a sub-directory in the upload location called “_old” (or something) and move them in there to be reviewed and managed. As we have clients’ sites that are over 5 years old, you can imagine the number of files that accumulate.. multiple versions of files, hundreds/thousands of entries, etc, etc. It really builds up over time. (I realize that some custom field types may not be supported in this type of tool).