Simple PowerShell Commands to find the Orphan Objects

To get the orphan objects on the specific content database please execute the below commands:

$CDB = Get-SPContentDatabase -identity "GUID of the content database"
$CDB.Repair($false) # $false to return the orphan objects

In order to clean the orphan objects, execute the below command:

$CDB.repair($true)

To get the GUID of specific content database attached to a web application, execute below commands:

$dbs = get-spwebapplication "Webapplication URL"
$dbs.ContentDatabases

Now you will get list of content databases attached to the web application and its details. Grab the content database ID from here and use it in your command.