Once a week is too much because it dries out their skin. My groomer told me that a cat should only have a bath when necessary, perhaps twice a year. Cats do an amazing job of keeping themselves clean so giving them a bath is not needed. Some older kitties need help keeping their back-ends clean but younger, healthy kitties should be able to do the job themselves.
Where's Jen? She's a groomer and give some great advice.
Life should NOT be a journey to the grave with the intention of arriving safely in an attractive and well preserved body, but rather to skid in sideways, champagne in one hand and strawberries in the other, body thoroughly used up, totally worn out, and screaming WOO HOO - What a Ride!
Sometimes the most real things in the world are the things we can't see
Until one has loved an animal, part of their soul remains unawakened.