The Deleted Objects object is itself a Container. Active Roles Server doesn't come with pre-configured Access Templates for manipulating Containers, but it is very simple to create a custom Access Template which can be linked to this Container in order to hide it from view.
This Access Template can be linked to the Deleted Objects container by right-clicking on it and choosing Delegate Control. You can then choose the Users and/or Groups whom you wish to restrict along with this new access template.
There is no need to restart any services or reset IIS. The Users will notice this change upon the next refresh or logon.