Just guessing this is it.
http://www.peachparts.com/shopforum/showthread.php?t=84138&highlight=%22oil+stop+leak%22
No experience either that the stuff hurts or helps. I have used many and never had an engine failure, but always continued leaking. Got to wonder if the leaks would have gotten worse w/o it. I've been using Bar's Stop leak. Under $2.00 for 20 oz. bottle, suppose the claims make me believe that it will slow down the oil filter housing gasket+oil pan leaks on my 300d. The stuff is not super thick like stp oil treatment, preferable with winter approaching.