They sell it in spray cans at the pet shops. It comes out like a foam, something like shaving cream and you just rub it all over the dog till he's very damp and then towel dry, they come out smelling so good.
I can't always find it here so I mix half and half water and cider vinegar and put it in a spray bottle and spray them down with this and massage it in real well, then I towel dry and groom them. Their fur comes out soft and shiny and it's a natural repellent at the same time. Good for their skin also.