I took my seedlings....3-4 inches, submersed the whole pot into a cooler of water, gently hoding the stem, and gently shook it. Most all of the dirt came off very easy....I transplanted directly into Lava Sand....which is my DWC medium....had about a weeks worth of TP shock, but they are doing fine!
I didnt use rockwool at all, instead went straight into my crushed lava medium.