Umm, I don't know. I know there was a mutiny among Hindu and Muslim soldiers for the Raj in India, after a rumor was spread that their cartridges (paper ones at this time, that you tore open with your teeth, and then poured the powder and ball down the barrel) were waxed with pig fat. As that is sort of, technically, maybe eating pig, they thought they had sinned terribly and been betrayed.

It wasn't actually true, though.

Now, if I was going to coat my weapons in something to terrify my enemy, I'd try poison. You never know, might work.