Outside, with the hose. We really don't bathe Gunnar or Daisy, I don't think Gunnar has had a bath since he was a pup, and Daisy, only if she gets really dirty. Neither of them smell or have skin issues. If we go to the beach or the lake and they swim, I hose them off when we get back. One of their favorite things to do is play with the water coming out of the hose so they get washed down a lot during the summer.
Bruzer, he gets bathed about every other month, in the kitchen sink.