SCOM 2012 Powershell command to remove agent

Question

Hello,
Has anyone had any luck removing agents via Powershell to mimic the delete agent from the console?
Blogs don't turn up anything useful for this task.
The 2012 Powershell covers how to approve agents, add proxy flag, and uninstall agent, but nothing to remove.  Used the SQL stored procedure previously in 2007R2 (and same procedure exists in 2012 SP1. 
Anyone aware of Powershell automate agent removal?
Thanks!
SCOM Power Shell to add SCOM 2012 agent
Get-SCOMPendingManagement | where {$_.AgentName -eq "ServernameFQDN"} | Approve-SCOMPendingManagement
Enable Proxy on newly added agent
Get-ScomAgent | where-object {$_.DisplayName -like "okcnmo*"} | where-object {$_.ProxyingEnabled.Value -eq $False} | Enable-SCOMAgentProxy
SQL Query to remove
http://social.technet.microsoft.com/Forums/en-US/operationsmanagergeneral/thread/e413c030-509b-45e4-bcd4-b4ae1a649c73
Uninstall Agent
http://technet.microsoft.com/library/hh545186.aspx
Remove Unix agents
http://social.technet.microsoft.com/Forums/en-US/operationsmanagerunixandlinux/thread/081f2801-7dfa-4db9-8c78-6adbc487a031/

Answer 1

We actually have used the stored procedure for 2007 and 2012
OperationsManager.dbo.p_TypedManagedEntityDelete
If you want to use Invoke-Sqlcmd to run the query.
Another way from SQL which can be put in PowerShell
--Grab GUID for that health service
select * from BaseManagedEntity
where FullName like '%<servername>%'
and IsDeleted = 1
Look for FullName with Microsoft.SystemCenter.HealthService:servername
-- Use this to test the entity delete for the healthservice GUID
DECLARE @EntityId uniqueidentifier;
DECLARE @TimeGenerated datetime;
-- change "GUID" to the ID of the invalid entity
SET @EntityId = '<GUID here>';
SET @TimeGenerated = getutcdate();
BEGIN TRANSACTION
EXEC dbo.p_TypedManagedEntityDelete @EntityId, @TimeGenerated;
COMMIT TRANSACTION
--Check what is in deleted
select * from BaseManagedEntity
where IsDeleted = 1