I just finished surgery on one of my hens and it was exactly as described.....really not for the faint of heart, but necessary nonetheless. I'm not sure if I got all the gunk out, but there sure was tons of it. It's amazing how tolerant chickens are. She was so good. She just laid there and let us do our surgery....crazy! Anyway, I soaked it in epsom salts to clean it, then again before I cut. There wasn't any scab (hole) visible until after I soaked it....it was weird. Anyway, then I cut the top of the foot open where there was a bulbous area coming up between the toes and fluid poured out. Then I cut the bottom of the foot and chunks of stuff came out. I thought it was done, but when I resoaked it, it still looked like there was something in it. So, I squeezed and prodded some more and another huge chunk of stuff came out and a black chunk??? I'm really hoping I got it all. How do you know?