Aislynn - I think the other girls on my team sanded their helmets, but didn't go so far as to try to remove stickers.
After six months of use, I have to say the helmets I worked on have stood up the best. The helmets the other girl glitterized have had some cracking/chipping off of the epoxy, and the epoxy has yellowed a bit while mine is still clear. I don't know what brand of the other girl used, but I used EnviroTex Lite
. Since it's been six months, I should probably get a new helmet anyway for safety reasons, but I love my glitter helmet!