PG-13 it and the results are awkward. In this case dirty jokes are both wrong and unfunny. Like a machine gun in a Pippy Longstocking movie, these dirty jokes feel incongruous. Most people would say yes. But I say no.
Talented people can turn the worst material into something that works.
Instead of writers hammering out ideas, they just turn it into an extended SNL bit. The list of failures rises higher than a Manhattan skyscraper. Had it not been written in the post-modern ironic style. Like the cartoon, it could have taken its subjects semi-serious, gave us a few scares, spouted nonsense about Scooby Snacks and protoplasm, and been done with it. Freddie Prinze Jr. will play Fred.