I put mine on my compost heap – works really well because they are thin. They break down really quickly.
They could also be used as mulch in the garden. You may want to spray them with water to weigh them down a bit so they don’t blow away with the wind.
I live in an old house with no insulation in the walls. I wonder if I went into the attic and dropped them down the wall cavities whether they would make any difference to the insulation of the house?