In the R77.30 SmartConsole menu select Search...Query Objects and change the "Refine by:" to "Unused objects" like this:
However before deleting objects that are reported as Unused, check the NAT tab of the object you are about to delete. If an automatic NAT rule is enabled for the object, deleting it may break something in your NAT configuration even though the object itself is unused. Taking a database revision before deleting any objects this way is strongly recommended just in case...
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