Glad to contribute something useful, then. As for methods, I also seem to be able to get it when (1) jumpslashing torch posts (black or wicker) just right or (2) jumpslash recoiling into a ledge hang.
Z+shielding to avoid the long fall animation lock is still on the 3ds.
There is alot of ways to get broken deku stick really.
Hitting two objects during the slash.
I even did it on a small stone, you just need to slash correctly.
-
Buffering with Farore's Wind menu should be added to the list. It allows you to buffer damage and such aswell.