I've tied them in black and tan down to size 20 with Maxima 4lb test. Caught a nice bow with the size 18 tan last year, but they were seriously schooled up. Probably could've caught one on all the monstrosities I've seen searching this site. I like to rib mine with fine gold wire for a little flash, it fits snuggly between the mono. I've collared them with peacock herl also.
I'm going to use this idea in a little bigger proportion for a green caddis larva and grannom pupae representation. Both show serious segmentation and I wonder if the translucence of mono would suggest gasses traped under the skin - a mechanism caddis use to emerge.
Let me know if anyone has any luck with these patterns!