MaJunior says:
I'm more concerned that Malice is an
inhaled poison, not an injury poison... coating your arrows with a gas wouldn't work.
True it is in inhaled poison.
[ +- ] Inhaled
These poisons are powders or gases that take effect when inhaled. Blowing the powder or releasing the gas subjects creatures in a 5-foot cube to its effect. The resulting cloud dissipates immediately afterward. Holding one’s breath is ineffective against inhaled poisons, as they affect nasal membranes, tear ducts, and other parts of the body.
It sounds like it is a smoke, and the idea is you would either open the vial and it would fill a square within reach or maybe throw it and when smashed it would fill the square it broke in. Neither sound like it is arrow friendly.