I needed horns for my black powder shooter. I found finding a horn was a chore. After some testing the way old timers did it, I came up with this. The boiling the horn and the smell it gave off in the kitchen tested me and my wife being married.
That came out nice. I used to boil and flatten them a little to make Scottish powder horns. I was threatened with bodily injury if I boiled them inside. I used the small side burner on the propane grill to do them outside.