The idea that artillery grunts can remove a nerve agent from a cw warhead and replace it with an inert liquid - and do so on a field of battle - is nonsensical. After all, what do you do with the sarin gas after it's removed? How do you store it? How do you dispose of it?
U.S. confirms ISIS computer expert killed in air strike (Reuters)
from the article: Defected Syrian general claims he was ordered to use chemical weapons