No I've not used ' media file guardian ' personally.
I prefer to use the native options in the phone to clear away files etc.
How did you download this application.
I've only had a brief look via a Google Search and can only see options via an Apk file , which I prefer to stay away from due to potential issues.
Daily Driver > Samsung Galaxy s²² Ultra 256Gb in Phantom Black.
The advice I offer is my own and does not represent Samsung’s position.
I have no affiliation with Samsung.