Well it's on the filter list, so someone must consider it more offensive than words not on the list such as "gaping poophole thrusting".

The "dirty" use seems pretty silly (sounds like something out of a crass 80's movie or something), but I can't really imagine using it in a non-dirty manner either. I mean I know people have hunted and trapped beavers, but when the capture them they don't just, like, thwack them with a giant cleaver, right? Would ruin the pelt if nothing else.