To bathe or not to bathe

Question
My wife and I are at odds overy bathing our yellow lab. I feel it is somewhat a useless activity. He constantly finds dirty or muddy water to play in, and will take advantage of rolling around in mud. I just can't see spending money on grooming him. An occassional bathtub adventure seems quite adequate. Am I being unreasonable in this.

Answer
Your wife won't like this answer.  Aster came to live with us at 10 years old over 3 years ago.  she hasn't had a bath since.  She gets lots of brushing and an occasional swim in the river.  this time of the year, I am using the wire slicker brush as pictured at  http://www.photolocker.net/images/Labman/knitanewaster.jpg  Once the dog dries off, you can remove most of the mud with a soft bristled brush.  Brushing usually is more pleasant for both man and beast.  

We get a new puppy every year.  I do bathe the females if they go through their season well after they are all done and the swelling is gone.  

Aster and my puppies are seen from time to time by those that would say something if I was neglecting their grooming.