I'm doing fem seeds in rockwool as will hydroponicly... I've had a high success rate with my buddies (my mentors). It's pretty simple and I'm sure you've done the same. This is their theory and it's worked for me!
I use distilled water into a cup and dump however many seeds plus one or two extra... just incase they don't sprout, if they do, more the marrier I say! I stick them into a dark place and wait for them to sink. Other's say to wait till they crack, but let's think 'bout that... if they sink, they're full of water, if they're full'a water, the seed HAD to crack to allow it in!!! Could be wrong, but thats my own logic!
Once they're cracked/sunk... I take a 1"x1" rockwool cube and soak it and put my lil' seedling in about 2mm deep and stick it under my hps (only light I use cuz I love autoflower strains) for 24hrs of light about 12-20inches from the bulb so they'll be warm and want to move up to the light.
It takes a 2-3 days at times before they sprout... but I still keep the light going at the same height untill I feel the little plants have made it through and established themselves with roots yeda yeda yeda....
after a few days of this and feel confident in them, I'll lower the light 4-5inches from the plants or untill it doesn't burn my hand (400w HPS i remind you) and switch them into a bigger 4x4inch rockwool cube and 20/4 or 18/6 light schedule.
After that it's just maintaining and care...
Hope I was able to help and good luck man! Just remember you can't win them all, but you definitely increase your chances with the right techniqe! I feel like everyone has a slightly different theory about it and there are sssoo many ways it can be done. I just recently saw a video on Youtube called "I grow chronic" by Mr. Green... check him out... he's very similar to my method, few differances, but same concept!
Cheers!