Those deal PHYSICAL damage while slow check is MAGICAL armor. Is this a joke? Literally unusable. Slow is rather shitty debuff as well and when I crafted them I expected at least solid earth damage or smth.
Imo in this case they should do just some trivial magical/phys damage so they won't be op. It is super easy to craft infinite oil/posion/water arrows in this game. Good damage+slow that bypasses armor would be too strong.