I used to have that problem, my ex sucked at tending a fire but at the same time felt compelled to mess with the fire. :( If they are small what I did was take a pair of sewing scissors and just cut out the burnt strands. At least with the damage I had you could not tell it had ever been burnt.
When we replaced the carpet and I laid tile in the kitchen I used some of the tile to create a three ft surround around the hearth of the fire place. Believe it or not he managed to roll a log past that. Can't for the life of me remember why I divorced such a brilliant man. :p