Some supporting info:
When I was experimenting with a small series drogue for use in towing our big inflatable
, I first made the cones from 1.5 oz spinnaker
cloth, and they were quickly destroyed.
I reason that this was because in this application, the cones are dragged along at six or seven knots, not the one or two knots when used in a full size drogue behind a yacht. The additional turbulence simply rips them to shreds in short order. This seems congruent with Ben's experience IMO.
For the dinghy
application I ended up using heavy Herculite vinyl cones and they have lasted for years now. Would be too heavy for a normal JSD...