Haha I never really thought about doing that. In general I just run behind the tree at the left of the exit door and wait for the gekkos to gang-up on me. It's easy to get parries that stun the geckos and enable you to round-house kick them in the face. If you get 3 zandatsus you're pretty much guaranteed an S rank.
I just try to get Aerial parries on the Gekkos, either that or perfect parry their jump attack. The timing is tight with Sam but it's fun to pull off.