Hi Tom,
Matchmen use this method on flooded rivers usually and I believe they fish either with a pole float set overdepth and a small running feeder above the hooklength (with the normal elasticated set-up) or with a flick-tip and just a feeder with bites being registered on the flick-tip.
To be perfectly honest, I can't see the point of useing it unless you're faced with a similar situation (ie difficulty in catching and feeding on a flooded river)as a straightforward pole rig and loosefeed/groundbait would be just as effective.