Yea you're probably going to have a really hard time beating the dogs. I've heard various rumors about coffee grounds and such but I dunno if it actually works. The best thing is just to not have anything on you or be careful about when you do.

I was out camping once when some cops showed up and I didnt have anything on me but one of my friends had an ounce on him and they had been smoking in his car the whole way down. There was like 6 cop cars. They must have had nothing else to do this was in the middle of nowhere. Anyways they did have some dogs out but the dogs musta been retarded cause the only "hit" they got was on another car who didnt have anything. He laughed as they searched his car and he showed them several zippers they missed. Meanwhile the friend with an ounce him was probably peeing his pants. I bet those werent even drug sniffing dogs. Probably just their pet.