They aren't cats.
I just take my beast into the tub or shower with me, the same way you would a very little kid. She's never been afraid of getting wet and I think she kind of likes the snuggles.
The vet says every week is fine. She gets dirty.
I use Earthbath Oatmeal shampoo, but my dog is kind of spoiled. The important thing is that dogs' Ph balance is different than humans'. You could just use dish soap with the right amount of vinegar or lemon juice. There are recipes on the internet.
I've got to brush her darned near every day, comb out fleas during flea season, keep her nails filed down, and clip the hair between her paw pads and these little tufts on her face that would grow into her eyes if I didn't.
She still looks like a scruffy little ragamuffin tomboy.
I don't love my dog because I think she's cute, I think my dog is cute because I love her.