This is just me tossing out ideas here....Buy the clones, take em home and put them in to a solo cup with some soiless medium ie sunshine mix ,pro mix. Allow 2 weeks for quarentine and veg in the sole cup, once you are sure they are healthy, carefully cut off the bottom of the solo cup and place in to your hydroton to allow the roots access to the water.
Edit: You could even put a little hydroton in to the bottom of the solo cup and cover it with the soiless medium. This would help reduce the amount of medium that could come loose in the water.