Good question !
I was looking for the same thing. Actually I have attempted to clone in insulation rockwool without success. Although I am a newbie grower I think I followed all the necessary steps which I have listed below and it died the 4th day.
- The cutting was three inches in length and was taken during the vegetative stage. It had 3 branches over the medium.
- Light 24/24.
- Humidity 90% the first 2 days and 70% the rest days. Temperature 25 C.
- Root hormone POKON powder.
According to my search, the link below explains that insulation rockwool has different properties and can't be used for agriculture.
http://grodan101.com/sw63706.php