Great idea!! I have heard of this technique being used for grape vines before. The way they do it is bend a lower branch down and cover it in soil once its rooted just cut it off the mother plant and you have a replacement vine..Would it be easier to burry a thin sheet of metal/plastic/wood under the soil and put couple of handfulls of soil ontop of the sheet then lay your branch in the soil and leave it for a couple of weeks or so to root, cut it off the mother plant then remove the sheet of metal/plastic ect.. and you should have some newly rooted clones?