I have used plastic dip & spray for other applications. Its a great product, but not very durable. Instead, I wrapped the mirror side ball with silicone tape that sticks to itself & it worked out well. I started at the top & held the end with my thumb & stretched it as far as it would go & wrapped it around overlapping a bit & finished at the bottom with a small circle where the tape doesn't cover. The clamp doesn't touch that section either.
I did a dual sport ride yesterday & it held up very well! I had put the original RAM balls back on & was impressed with much less vibration except at highway speeds (15/50 gearing on a DRZ at ~6500 RPM). Next I will put back on the hotrodwelding balls & wrap them with the tape & report back.