Deleting clients from WSUS using powershell


Am list of servers that have been deleted in AD and am planning to delete them as well in our WSUS server. I am using below code to delete the devices but it is not working. Hoping that someone could help me check what is wrong with the code. Thanks in Advance guys.

$Computername = ‘WSUSServer’
$UseSSL = $False
$Port = 8530

[reflection.assembly]::LoadWithPartialName(“Microsoft.UpdateServices.Administration”) | Out-Null
$Wsus = [Microsoft.UpdateServices.Administration.AdminProxy]::GetUpdateServer($Computername,$UseSSL,$Port)
$Group = $wsus.GetComputerTargetGroup(‘a0a08746-4dbe-4a37-9adf-9e7652c0b421’)
$Clients = Get-Content C:\BackUp\PScripts\SDO\serverlist.txt
$Device = $Wsus.SearchComputerTargets($Clients)