Deleting files with Remove-IshDocumentObj Tridion 13 SP1

Is Remove-IshDocumentObj still supported in Tridion 13 SP1?

For example, when running:

Get-IshFolder -IshSession $ishSession -FolderID $parentFolderID -Recurse | Get-IshFolderContent | Remove-IshDocumentObj        #removes all documents within a parent folder

The metadata for the files is deleted, but not the actual files themselves. What is the correct way to completely delete a file?