Well to be honest man i have success both ways belive it or not. I experimented with clone into soil and rock wool. I think soil is more forgiving(moisture level easier to manage) Rockwool likes to be pre-soked then kept moist, not dry and not wet. Humidity is key tho...Must have dome i have realized!
A small cfl not directly over clones...6-12 inches away. I take 40-50 cuttings at a time and i use (3) 2700k 40 watt cfl's. Works perfect. I started using a heat pad and results came even quicker.
Any local grow shop will have your rockwool.$5-$10 for a slab of 40 cubes.
I am taking more cuttings today actually...cant wait!
Respect