Recently I developed small page for managing Sitecore Media Cache folder. The code is not entirely mine, I started with scripts found on the web, but in the end modified it almost completely.
The reason why I developed it, was to have the ability to test Dianoga image optimization on Azure Web Apps, where you don’t have direct access to Sitecore MediaCache folder (placed in d:\local\MediaCache) via Kudu console.
What it does?
The page lists files from Sitecore Media Cache folder for given Sitecore item ID from Media Library.
It allows also to remove cached files for this media item ID, or delete all sub-directories in MediaCache folder (to clear whole cache).
Just paste clear-mediacache.aspx to site root folder in your CM or CD instance and run it.