It seems you already have a plan of action but I'd like to throw my suggestion out there as it has worked flawlessly for me. What I do is grease the underbelly of a frozen fish (Chinook salmon work best IMHO as they are vertically stiff and laterally squishy) and bash it against the precise (prescision counts a ton here!) location to be cut. Should have a clean slice within the first three to 50 whacks if you're doing it right.
If all else fails, call Mr Duggan; I hear he's a whiz with a 2x4.