How do I remove sticker residue from gl?

I purchased some clear gl plates that were sold individually, and had the bar code stickers on the bottom. I have tried all I can think of to completely remove the stickers, and yet there they sit. I've tried soaking in paint thinner, nail polish remover, orange juice, Goo Gone, scrapping with a razor blade, CLR, and that $22.00 bottle of crap the guy at the hardware store insisted would work . I even set them in the fireplace to try burning the reside off, and all it did was turn the sticky gunk black. They look thorrible! II'm at a loss. Aside from buying new plates, any suggestions will be tries. Thanks~