Yes no problem. I put clones from rockwool cubes straight into soil with no probs. Once I even put a clone into rockwool...into soil... then later into a bigger pot of pea gravel and turned hydro on that plant and still no probs so
yeah it will work
FFOF may be a little to high in nutes for the clones and burn them, I go into fert free soil to start but I am thinking about trying FF Light Warrior on my next ones.