MGibster
Legend
The characters live in a very different world from us. In real life, there is some sort of meaningful benefit to taking a bath every now and then. It might be hard to quantify, but it makes you feel better. There's a good reason for you to act in this way.
I gotta think basic hygiene is just one of the many things that isn't specifically covered in most game books for two reasons: Hygiene just isn't where the story is focused and because of the limitations imposed by time and the print medium you can't have rules for every conceivable situation. Not even GURPS can do that. (That's right, GURPS! I'm calling you out.) It's just assumed that characters take care of their equipment, go to the bathroom, and groom themselves and this isn't something we need detailed in the rules.