I just did it, and I think it keeps the spokes from vibrating and snapping, and it is HARD to get it out, i cant get em outta my front yak, so i ride a pro whee; in front i got like 1/4 of it out ill have by like 3 days.
one tip, take your time and let the glue get really really hot, dont force it out, it comes out 10 times better because when its hot its can fill up more like a liquid and it will fill in everything instead of coming out shitty. i didnt sand this wheel or anything, this is how it came out.