I use them all the time for clones. I have 2 Jiffy-7 propogating trays with heaters and domes.each will hold up to 72 peat plugs. Works so well I bought a second unit so I could clone large numbers for the outdoors.
sorry to add to the list of "likers" of the peat moss pellets, but i love them. Im a soil grower and its really easy to transplant the pellets when planting clones into pots. I have had 100% success , rooting clones and sprouting seeds with peat moss pellets