Umbilical granuloma

Holli
Anybody else had to have one treated for their baby?
I just took my girl to the doctor yesterday to have it cauterized with silver nitrate and it went well.. 
But I'm not sure how it's suppose to look while it is healing.. It's all grey around it and starting to look a little gross.. But maybe that's normal?
All the doctor said is that it would maybe turn white. 
Curious to hear other experiences with this.