Goof Off has to be the best product ever when you need to remove last years decorations from your classroom
Do your desks have a film on them from name plates and packaging tape? Spray this on the desks. Let sit. Then wipe off.
The laminated poster you made las year have permanent marker or dry erase marker left on it? Spray and wipe! It's awesome. No more hairspray or nail polish remover.
Of course you wouldn't want to use this product with students in the room. Strictly for summer cleaning or at home use. You can buy it at Lowes or Home Depot for less than $10 (when I bought my bottle).