Fish the clinch quite often, and have never tried a SJ worm. I have some in my box, but never think to tie one on. I have caught lots of fish in the 15 to 18" range this year on #20 zebra midges & BHPT's, and my large brown came on a #18 sulfur thorax. However, I think for more consistent big brown action one should throw an olive streamer, either a wooly bugger or a slumpbuster. Also, it wouldn't hurt to throw a worm, you may just be surprised with your results.