Passing the beans through the guts of an animal is not going to deter a coffee 'hound'. One of my favorite sets of books is the Patrick O'Brian "Aubrey - Maturin" series. In one of the episodes the main characters, ardent coffee drinkers, are bemused by the off-taste of the brew. Killock, the Captain's servant informs them that rats had got into the beans so he'd had to brew with rat turds. The men comment on this while drinking up every drop.

I've always felt this was so extreme, it must have happened.