Changed your suggestion to:

 Code:
$objComputer = GetObject("WinNT://"+@WKSTA)
$arrFilter[0] = "User"
$objComputer.Filter = $arrFilter
For Each $objUser in $objComputer
  if $objUser.Name = "unwanted"
    ? $objUser.Name
    ? "Unwanted User detected, trying to delete..."
    $objUser.Delete
    
  EndIf
Next


and the user gets detected.
There is no error message, but the local user is not deleted.