Buddy Wash is the only shampoo I will use. It doesn't have "soap" in it and it's more natural than most human products. It really does get them clean though - mine go outside and they do get stinky by the end of the week and this gets them so clean. I find the smell does last for at least a few days. My groomer even switched to it because she said it doesn't dry out her hands using it every day. She dilutes it so it rinses better and lasts longer. I love that I can use it on their faces and I LOVE the smell.
When I get the spray bottle out they run away like "NO!! She's going to make us pretty!"