All you need to make this mess disappear is some dryer sheets, paper towels and an old bath towel.
Set the iron on high so it preheats and fold the bath towel in half to use as your work surface for cleaning.
Lay a couple of dryer sheets on the towel and have some paper towels nearby.
Iron over the dryer sheets several times with the hot iron and then iron the paper towels.
The dryer sheet will soften the burned on mess from the bottom of your iron, the paper towel will absorb the softened mess and remove it from the iron.
Depending on the amount of build-up you may need to repeat this process several times.
A nice clean iron that won't leave residue on your clothes! I'm Mrs. Fixit and it's just that simple!