Why wouldn't this work? Here's a hydro system that I think would grow monster plants (soil growers, you can choose to avoid reading this if you are bored by such contraptions!):
I'm considering making a combo "top drip" x DWC hydro unit for fun, too. My thinking is, a tote with a botanicare flood fitting/risers keeping the DWC water level consistant, while a top dripper periodically waters from the top down. The drippers are pulling from a secondary res that is recirculated through the flood risers in the unit that contains the plant. (the main reservoir is below, and gravity will be what returns the overflow to the main res underneath through the flood fitting).
Don't know if I explained that properly, but when the drippers water from the top, the excess they add to the unit will drain back through the flood fitting to the reservoir, which is in turn feeding the drippers, etc. With this, there would only be the drain through the flood risers, to maintain an ideal nutrient level in the "local" reservoir at all times. This would be connected to a main reservoir that feeds the drippers, and accepts the overflow through the flood risers. (There is no flooding with this, the flood riser is just for maintaining a consistant elevated level for the DWC portion of this, while still giving the ability to top drip and recirculate somewhat).
Just throwing this out there for inspiration, or for someone to shoot holes in before I try it myself for fun... I have a friend that grows with a combo top drip, dwc in buckets much like the one I did the Big Bang Auto in. He's done some comparisons to just the DWC bucket and is getting much better results with the drip added. Obviously, the Big Bang Auto was a good yielder, so this got me thinking... love any feedback/thoughts. I'm not sure when I'll get around to this, but thought I'd throw it out there.