I am switching from rockwool to coco also, and have ordered some of the CocoTek AB cubes for my ebb/flow.

I will use them for rooted clones, then plant into a 5 1/2 inch sq pot with some Ready Gro and loose coco filling up the pot. So far I have been using the rockwool cubes with the Ready Gro in the same manner (no coco).

Good luck, and I'll report on how it goes.