David, I'm sorry nobody responded to your first post a few days ago. I don't know which Dracaena you are thinking of converting to hydroponics but I don't know why you shouldn't give it a try!
Lucky Bamboo (Dracaena sanderiana) is sometimes grown strictly in water. I had a D. braunii growing in water for years. I got unrooted cuttings from somewhere and put them in a vase of water. I don't remember how long it took for those stems to produce roots but once roots appeared I put some pebbles in the bottom of the vase to weigh it down and to keep the water from stagnating, I'd empty the vase every few weeks and replace with fresh water. My plant grew like that for @ 6 or 7 years before I decided to pot it in soil.
If your plant has roots you should wash away as much soil as possible before putting it in the water to grow hydroponically.
