Here are relevant references from the Books where a bosk whips are mentioned.
I make no pronouncements on these matters, but report them as I find them.
Arrive at your own conclusions.
I wish you well,
Beside him, coiled, perhaps as a symbol of power, lay a bosk whip.
Nomads of Gor Book 4 Page 43
Near the animal, on the turf, a long bosk whip was laid in a circle, having a diameter of somewhere between eight and ten feet.
Nomads of Gor Book 4 Page 70
It was scarcely ten beats and Conrad had bound the struggling, scratching Tuka, slung her about the pommel, raced back, kaiila squealing, and threw the girl, wrists tied to her ankles, to the turf inside the circle of the boskhide whip.
It was not the five-bladed slave whip, invented for the full and perfect punishment of an erring slave girl, but only a light, one-bladed bosk whip, little more than a switch of leather, a mere incitement and encouragement to better performance on the part of a slacking plow beast, but it struck my back like a hot snake and a rifle shot. I could not believe what it felt like. It was the first time I had ever been struck with a whip.
A whip is used with bosk or kaiila, but it serves little purpose with tharlarion, given the thickness of their hide, and their comparative lack of responsiveness.