I know, there was a thread about the Bars leak stuff, but I deleted them all because "when would I ever need it".  Right...  Now, that my head leaks coolant out at the rubber gasket, I went to the store and read the instructions.  I think, it is only good for conventional engines, but I could be wrong.  
By the istructions, I would have to empty the antifreeze coolant and flush the whole system, including the heater cores and only then use the stuff.  The empty and reinstall antifreeze.
I am not sure, if its the kind of thing that would work with my head leak, which is not very bad yet and only started doing it.  
So, shell I use it or take engine out?
Zoltan