If you're not opposed to a little mod that you can write yourself, consider this. It's a throwing javelin that does zero damage and doesn't require a fire to make (since it isn't a real weapon, it doesn't need to be hardened.) It's not everyone's cup of tea to mod their game, I understand that, but for me this fits with the game just fine. Regular javelins will kill things very quickly, and since you need a live target to get quality practice, it makes sense to have a low damage training weapon, equivalent to wooden swords or sticks for practicing sword fighting techniques. Just add these lines to your diy_glossary.txt file and the training javelin will show up under the Weapons menu for crafting.
.Training Javelin. "Javelin" [effort:1] [phys:hands,one-armed] *COMMON* /20/ [patch]
{Staff} [remove] [patchwise]
{Cutting weapon} <Axe>
[BLUNT_ATTACK:0]
[POINT_ATTACK:0]
I like to whip up a big pile of these things and then make an AutoHotkey macro to throw them, saves a ton of keystrokes.