Do you have a tray with humitity dome? If so, or a DIY thingy on maybe a cake pan with a plastic rap tent, just put a very thin layer of water at the bottom, very thin, about as thin as your finger nail and put the cubes with the clones in it. Mist the plastic and in about a week they shoud pop out some roots. Don't let the RW cubes become saturated just a little moist, the thin layer of water will do this for you, because the cubes will soak up the water as needed.
Adieu