Believe it or not, regular Dawn dish washing detergent (one drop mixed with 3 cups of water) will do a good job. Followed by a coat condition (oatmeal based is good)
Dawn is safe to use on pets and wildlife. I use it all the time and have for 20 15 yrs. Remember it has to be VERY diluted, a little goes a very long way.
*** It's not a sexy little shampoo in a cute as a button bottle, but you can spend the extra $$ on the coat conditioner. My yorkies have always had great skin, shiny coats and are very very bunny rabbit soft. I do not use it on puppies under 8 months.
Just sharing ...one of my ways to save a few pennies, I bath my dog 1-2 times a week.