This is a good idea !! Eliminate the tangle of unused extension cords by storing each one in a piece of pipe insulation-foam tubing with a slit along one side.
Using a utility knife cut insulation to desired length(about 13 inches for each six feet of cord.
Fold the cord to size,insert it,and label foam to indicate the length of cord enclosed.
This might be a good one to have ready when you start to take your holiday decorations down for the year.