Here is a post from a few years ago.
Ta Graham H for reminding me.
I have managed a large number of barbel on the St Pats and Loddon over the years using the method I class as stret pegging. It is ideal to fish between streamer weed or deeper inside line drop offs.
Firstly you will need a powerful float rod / tench rod ideally 13ft to get max benefit. I would use 6-9lb line.
The most important aspect is the depth youset the float and you fish at. This should be set a nominal 9 inches to 1 foot overdepth. My choice of float would be at least a 5bb stick.
The float must be attached top/bottom.
Also, unusually, you should bulk most of the shot about 6 inches or slightly more from the hook.
AND have more shot on the line than the float can take...at least 2 bb.
The whole idea is to work the bait downstream, in stages, in line with your rod tip after casting out downstream just below level with where you are sitting.
You will find that the float will swing around (weed permitting) being tautish with your tip.
I would put the rod in the rod rest, and every now and again pull off a foot or so of line to work the swim, after a slight lift of the tip.
The whole idea is to get the hookbait moving with the currents flow, up, down and across, searching between the weed. You will find that the float will sometimes lay flat, as per the example you mentioned with MB. I would suggest he was just using the Quill as an indicater rather than true stret pegging.
You will find that the float will sometimes drag under, sometimes lay a bit flat etc.
BUt Bites will be like a typical barbel bite.....wham.
Most succesful for me was with using tares nicked on a size 12 hook and feeding hemp at my feet little and often. Of course maggots/casters etc. your choice.
Hope it all makes sense. Not unlike very light legering really.
Graham