I've seen several examples where Marshal.ReleaseComObject() is used with Excel Interop objects (i.e., objects from namespace Microsoft.Office.Interop.Excel), but I've seen it used to various degrees.

I'm wondering if I can get away with something like this:

var application = new ApplicationClass();
try
{
    // do work with application, workbooks, worksheets, cells, etc.
}
finally
{
    Marashal.ReleaseComObject(application)
}

Or if I need to release every single object created, as in this method:

public void CreateExcelWorkbookWithSingleSheet()
{
    var application = new ApplicationClass();
    var workbook = application.Workbooks.Add(_missing);
    var worksheets = workbook.Worksheets;
    for (var worksheetIndex = 1; worksheetIndex < worksheets.Count; worksheetIndex++)
    {
        var worksheet = (WorksheetClass)worksheets[worksheetIndex];
        worksheet.Delete();
        Marshal.ReleaseComObject(worksheet);
    }
    workbook.SaveAs(
        WorkbookPath, _missing, _missing, _missing, _missing, _missing,
        XlSaveAsAccessMode.xlExclusive, _missing, _missing, _missing, _missing, _missing);
    workbook.Close(true, _missing, _missing);
    application.Quit();
    Marshal.ReleaseComObject(worksheets);
    Marshal.ReleaseComObject(workbook);
    Marshal.ReleaseComObject(application);
}

What prompted me to ask this question is that, being the LINQ devotee I am, I really want to do something like this:

var worksheetNames = worksheets.Cast<Worksheet>().Select(ws => ws.Name);

...but I'm concerned I'll end up with memory leaks or ghost processes if I don't release each worksheet (ws) object.

Any insight on this would be appreciated.