Has anyone tried a rubberized coating on older Klipsch tweeters?

Mr Decibel here on audiogon has done some treatments 

Thanks !

Not tweeters, but I have used a product similar to dynamat,  peel-off rubber like sheets meant for this purpose on the outside of the horns on my Epic CF-4's. I did 2 layers and it was effective, but I wasn't having an issue with brightness, I just wanted to make it more dead, and to compensate for the fact that it's plastic, not thicker wood.  

Thanks roxy54!

Dynamat was the material I used as well.