My Iso-caine ( 2.0 version with new materials) is the closest thing to fishing a dirty and deadly night-crawler for big browns. This wiggle nymph with its marabou tail, articulation and wiggling/jiggling action due to the micro tungsten head and the rod and stripping imparting stutter jerks and pulses, is deadly when fished down-and-across in classic wet fly/soft hackle fashion. Trout target fast swimming Isonychia nymphs and show explosive rises to them, eating both the adults and nymphs just under the surface.This pattern is lethal fished all day ( bright sunny weather) and in pre-hatch periods, as these wild Catskill browns struck on a bluebird day on the Delaware and Neversink.
My new online magazine launching in a few weeks will featutre exciting patterns like this that convey the science , asrt and passionate tactical chase fro trout/salmon/steelhead in a whole new venue