It would take approximately 10 STARVING lactating sows to fully dispose of a body. You'd have to be prepared a week or two out to let the pigs starve so they'd be hungry enough to eat a person. They eat approximately 10-14 lbs of feed in a sitting. Hair and teeth prove as evidence after the fact because it can't be digested fully. Most of the time when there are instances of pigs eating people they only eat parts of them, not all of them because they're not hungry enough.
And none of this matters on the WC farm because there weren't even pigs there. (And sorry that I responded to yours and not the other persons--- I'm still learning how to do all of this.)