Cloning machines, regardless of the type have their own problems -- the main one being getting slime mold or other organisms into the system and then failing ot properly clean the system before reusing it -- but they can be very productive too.
Personally, I like cloning into Oasis cubes because they are a lot less work to prepare than rockwool and if you are going to use them in hydro the peat based blocks, regardless of shape MAY leach through your grow media after transplanting and mess up your pumps or other parts of your system.
Another newer alternative to rockwool is Sure To Grow which is very similar to rockwool in use and growing procedures except that it does NOT have to be conditioned ahead of time because it is instantly wettable, PH neutral, chemically inert and sterile. It is made from PET1 plastic and they are introducing a certified organic version that is biodegradable. In fact it is my understanding that once the organic/biodegradable version is in main stream production, they are going to discontinue the current, but I could be wrong.
The main things that I have discovered are keeping the stem of the cutting moist, or even wet and preferably in the dark, but I've seen my mother clone plants by just putting the cuttings in a glass jar of water and put it in the kitchen window sill. Another thing is you have to keep them WARM -- at least over 65F or they will not root! I learned that the hard way with 2 batches of clones -- did every thing identically bur 0% success until I remembered it was staying about 70F at night so once I moved them into the veg room where it was warmer, they started rooting again.
Good smoking.
