personally, i've eliminated rockwool from my garden almost entirely.
i still germinate my seeds in rockwool because i've had 99.9% pop.

anyway, i built myself a bubble cloner that i put 2 drops of Superthrive into
and, like 7 days later, i get roots. it usually takes about 2 weeks to get a
solid little root system established and ready for transplant.

when they are ready, i just put them into pots filled with hydroton.
like this.

lol, justanother2cents, fwiw