I LOVE BuddyWash. You can buy it at Whole Foods. They also sell a GREAT conditioning spray.
I only wash Thor every 2-4 weeks. I believe it is better for his skin. I do wash his hiney if some poop gets stuck on it, but we've gotten pretty good at just targeting that area. He knows to stand with his butt in the water and his front paws on the edge of the sink.
I do run a wet comb through his beard whenever it seems to be getting narsty - I brush his teeth every night, and toothpaste gets stuck in it, which then sticks to everything else.
Thor does not smell (at least, I don't think so!) but there are a lot of good sprays you can use in between washes.