I just gave my yellow lab Jessie his first bath in a while a few weeks back. He was filthy before, to the point of where if you pet him for too long, there would be a layer of dirt on your hands. He got a nice bath a couple weeks back, and he was all puffy and clean. For a few days, that is. Then he went right back to being just as filthy. I tried my best to keep him clean, I brush him just about every other day, which he shouldn't need it that much, and I wipe him down with a wet paper towel every day. No matter what I do, he stays filthy. I can't really wash him every couple weeks, I don't have that much time, nor do I have the money to send him to the groomers every couple weeks. Is there anything I can do to keep him clean? Use better shampoo? Monitor his outdoor time?