I tried it today out on the stream. I ended up taking a small rubber band, doubling it over and sliding it on the rod butt. I could easily slide this up and down the rod butt to secure my dropper nymph. And I just left it in place while I was fishing

Gear Ties are a cool product with many uses. However, I didn't like them for this application. I wanted something that I could just leave in place on the rod so I wouldn't have to fumble getting something out of a pocket. And the Gear Ties seemed to be too big, intrusive to leave in place while casting and fishing.