I start mine in little dirt disks called jiffy pellets let them get its first true set of leaves and the roots will just be at the bottom then straight into the bubbler
you can do it ya just rinse the dirt off under running water and stick it in the rockwool cut down the middle -this guy just sticks it straight into the expanded clay (soil can have nasties though so it's probably not ideal)[video=youtube_share;ZCfdiEGzmqg]http://youtu.be/ZCfdiEGzmqg[/video]
Just start em in something like a peat pellet/rockwool cube/rapid rooter (my favorite) and
put em straight in the hydroton. Just make sure you top water them daily until the roots
hit water.