I stricktly use jiffy pucks, they are the easiest way i have been able to clone. 100% success with them, in 7 days they root, 7" humidome, 23watt cfl, 22 watt heatmat. the heatmat and the tall dome are what helped me go from about 60% success to 100% success every time .you just plop them right into your medium of choice once they root and your off and running. dont know how long you can leave them in (with no medium) the pucks.
If your interested I'll spell out my cloning technique in detail, it works out real good, and fast. I also do a "pre-veg" that in my opinion helps out a ton during veg, and that pays off in flower, its all about the roots.
Good luck