Yes 5 sounds about right for your first go ....[If you want all to sprout try germinating in toilet roll]

Place about 7 sheets on a plate or in a plastic box and drizzle a good amount of water on and allow the tissue to get fully wet..then place the seeds onto the tissue and lightly press them down so they get a foot hold. then place another 7 sheets over the seeds and add water,drip by drip, untill the tissue is nice and spongey!!! . leave them in a warm dark ,small space[cupboard styley] and most should have popped in 1-2 days ...I just germed ALL of my seeds except those that were DAMAGED!!!! .....try it ..even with tap water! check them by lightly peircing and removing the tissue with a knife..if they haven't popped , simply replace the same peice of tissue with the knife and pat it back down over the bean.
5 first time but even if they don't pop you can still use them for a second attempt elsewhere.
Deisel..Soma?
Once they have cracked CAREFULLY place them 'sproutdown' into your pre soaked rockwool cubes ...Just water first of all IMO