This is how I solve the problem of musa-sprouting, with pictures.
The equipment I use: Reptile heating mat, el. timer, and plastic boxes with lids. I place the setup in a cold room, in my case our bedroom. I keep it on for 10 hrs and off for 14 hrs. This means 10 hrs of 25-30 degrees C and 14 hrs. of 13-18 degrees C.
In a matter of 1 week to 3 months, most seeds should sprout. I am so excited, that I check atleast 3 times a week for white roots. In this case, musa sikkimensis has sprouted well.
I pot them up immediately, after I see some roots & shoots. I use drinking cups, with holes made in the bottom for drainage. The soil should be well draining. I use cactus soil with perlite. This means frequent watering!
The seedlings grow extremely slow the first month, I have found good light conditions and movement of air is beneficial to reduce the problem of "damping off". This has never really been a big issue here, but it does occur.
After 3 months of good growth with fertilizer, sunlight, and watering my musa helen looks like this.
Best of luck to everyone who wants to grow from seed!
Erlend