NAV 11.x and wondering how to bulk deleting files form Quarantine

It seems that I must delete files in the quarantine folder one at a time.  But, alas, I find there are 1,123 of them.  Is there not a way to delete multiple files at once?  And, secondly, how do I authorize an auto deletion of quarantined files?  Preferences seems to allow neither action.

 

Thanks