According to
this thread, GA-3 is useless for bananas. But if you want to experiment, don't let me or anyone else discourage you!
I would think testing different mediums (sterile vs. non-sterile), different pH, and temperature regimes would also be a good approach. Apparently, knicking seeds has become an issue again. I have never done anything more with sikkimensis than soak them for a few days and put them in a 14/10 cold-warm regime. These seem to sprout fairly easily for me.
Erlend