Hey bro all I know about DWC is that you need a bubbling system, sterile water, and a humid environment usually controlled by a plastic dome over all of that.
I also know that while cuttings are taking root they feed primarily through their leaves, which is the reason humidity is the #1 most important part of cloning. My advice on this is to keep your medium moist and keep the atmosphere where the leaves are between 75-90% humidity.
My experience has been that my plants had started growing roots in a humid 90 degree farenheight environment under a plastic dome with CFL between 8-12 days. I'm not sure if this is typical, but I have read many people say it takes around 10 days, and my experience has been roughly 10 as well.
Also I know you didn't ask, but I just want to throw in my biggest mistake at first with this was heat, it killed several generations of my clones. Make sure your environment doesn't ever get over 90 degrees!
Hope this helps, good luck dude!