Hello Egon,
just one info, "ardoc delete" deletes only indexes, not the document behind in the object server.
Either the object server is configured to delete document automagically after X years, or it won't delete them.
So if you are legally bounded to delete documents (as we are in Switzerland), then arsdoc delete won't do the trick because technically the document is still somewhere, not easily accessible, but still there.
Sincerely yours,
Alessandro