I absolutely played them before. Probably multiple times... I've heard the cookie monster kind of gutteral singing he does by other vocalists, so I guess it's a thing but I don't think its so common for this genre hehe. It does give it a comical feel, but for me it works because of the vibe. This band is definitely all about having a good time, their level of ridiculousness is one of my favorite things lol.
It's a good time, I highly recommend you get on that. ;D