Take the cotton item outside. Shake off the excess soot.
Lay the cotton item on a flat surface with the soot stain facing upward.
Rub a pre-wash stain treatment into the soot stain. Allow the stain treatment to soak into the stain for 15 minutes.
Launder the cotton item in cool water.
Examine the progress of the soot stain. It may take several washing to completely remove the soot stains from cotton. If the stain is still visible, lay the item on a flat surface with the stain facing upward.
Saturate a sponge in rubbing alcohol and blot the soot stain for several seconds. Launder once again.