TOPIC:

Be carefull with sticky remover...  I killed a radio with a dry towel wich I used to remove duct tape 

I chipped mine off with a hard edge and a wire brush. 

I did as similar. Using a hard edge (my finger nails) was the key. Finger nails have the exact needed hardness to break of the dried ballon in micro pieces but avoid damaging the plastic. Obviously I was lucky the dried ballon parts were not that sticky to the surface. Thx