Fish two streamers on a very similar rig (I use a dropper loop instead of a ring) often. However, I'm usually using a shooting head and unweighted flies. I suspect you'll find that you'll want to use a heavy stiff tippet material for the dropper to minimize tangling. Rig will be higher maintenance than a single fly rig, and a bit more than a traditional two-fly stem (i.e. off the bend), but it does work.