WARNING!!! This will delete ALL VMs in your vCD!!!!!
Connect to your vCD with “Connect-CIServer
Stop-CIVApp * -Confirm:$false
Remove-CIVApp * -Confirm:$false
sleep 5
Remove-OrgNetwork * -Confirm:$false
Then manually delete any gateway devices and then run the following to clean up all the orgs:
Set-OrgVdc -Enabled:$false
remove-OrgVdc -Confirm:$false
Set-Org -Enabled:$false
remove-Org -Confirm:$false
Big thanks to my colleague Grant Voss for this awesome little cleanup script.