You would not BELIEVE the glorious pile of Ah My 
Goddess movie cels I picked up at the Boston 
Anime convention today, and at really great 
prices. I may not ever have to buy an AMG movie 
cel again.  But I digress, that's another story...

Most of these cels were not in cel bags, and some 
are a bit grubby around the edges from the 
fingerprints of me and other people handling them.

What's a safe and effective way to remove this 
grub from the cels?  It does not involve the 
lines or paint, it's all in the couple of inches 
around the edges.