Not for the squeamish,
http://www.youtube.com/watch?v=4y_Ylfub0_4
Helps if you understand Turkish also, but heres a very informative series of videos dealing with how goatskin bags are processed.
It did not show the slaughtering! Nor the skinning!
So it was quite safe to watch 
Interesting. What did he mix in the red bowl?
My Bulgarian Gaida had a goat bag, in which the hairs were left on the skin. It was just turned inside out, so the hairs were inside.
No bag proofing was needed.
~Hans
Certainly not pure salt, like the Bulgarian gaida makers use. There must be a reason why he wears gloves and a respiration protector.
I know in Hungary and neigbouring countries they use alum. It doesn’t require a respirator, though.