I do not remember if they only used a jackal hide for one thing in this book, but I do know that they used one just about first thing after they got shipwrecked.
Very early in the time that they are on the island, they are attacked by jackals. The dogs fight some of them off and Fritz kills at least one jackal. In the fight, the dogs get hurt when the jackals bite them. The family figures out that they could prevent the dogs from getting hurt in fights if they would just make spiked collars for the dogs.
So they make spiked collars. They use the jackal hide for the collars and drive nails through the hides for spikes.
During this same episode, Jack makes a belt for himself out of the jackal hide.