I have never had any kind of success cloning in rockwool. I hate that stuff anyway. I have had close to 100% in both my cheapo areocloner, and in soil. Search the cloner if your interested in building a simple fantastic device. If putting in soil, it's real easy; Just flood the non fertilized soil once before planting the clone with water and a couple drops of B1 like SuperThrive PH'd to 6.8, scarify the clone, dip it rooting hormone, poke a hole in the soil and plant the thing. Keep it and the soil warm and moist however you want, and it will root within a couple weeks, providing you cut the clone from a good area of the mother. Use a humidity dome or mist or use anti-wilt. Harden after they get about 3 inches of good root.