I put my Lab directly in the shower, and kneel beside the shower to shampoo her (my shower is separate from the bath, which makes it easier). I use a large plastic container to rinse her well. I end up having to shower right afterwards, but it's a small consideration when you weigh the options: my groomer charges $1 per pound for bathing, and my dog weighs about 80 lbs...
A "telephone" type showerhead might be another option. It would be easier to rinse with a longer cable.
Hope that helps!