Here's idea #999 in the list of bad ideas - can't be the worst idea, which would be a bed of nails, and it can't be the second-worst idea, whcih is a bed of slightly less sharp nails. Why not fold some blankets and use those for sofa cushions?

Because . .  . they won't stay stacked? Because people will sink into the pile and jam their knees into their eye sockets?