I was having problems cloning Rosey until I switched to two small tupperware little dishes now everything roots. I think the tray and prop-dome were to big for the amount of clones I was working with, I couldn't keep the humidity high enough and they would be dead within a couple days.
When I switched to little tupperware containers it kept the humidity high and I barely even had to spray them, I filled the bottom of the container full of jiffy pucks, about 6/7 fit. I found a small amount of rooting hormone and inserting the clone then squeezing all the excess water out. I wedge them in the container pretty tightly, I haven't had roots grow from one to the next yet but I check them daily. I also move my plants around a lot, I found filling the container full of pucks even if I wasn't using them all kept the clones from moving around.