Unless you are showing your cat, trying to control matting , or have a particular breed that requires it (Like the sphynx, I believe) it isn't really needed. I would still do it occasionally just to keep the cat somewhat accustomed to it in case it is needed in the future (oil on coat, skunk issues etc).
A good brushing should take care of any excess dirt before he comes into the house. i have taken a damp washcloth and wiped them down too. I have NEVER bathed my cats unless they have diarrhea or something really nasty on them, I have a 15 year old that has never been bathed. Cats are not like dogs, tehy have no odors (unless they are Siamese, or some other breed that has a distinctive smell.) But that odor is normal and doesn't go away no matter how much they are bathed. Cats are self cleaning and shouldn't need bathed unless absolutely necessary, that's why most dislike water!
My boy is a DSH and I brush his coat every morning. Once in awhile I use a slightly damp cloth to wipe him over or unless he soil himself in the litter box or fall into the toilet bowl :lol3:
Never bathe him before and he never smell as he sleeps next to me on my bed every night.
The only times I've ever bathed my cat(s) have been when they've gotten into something that would be dangerous for them to lick off, like charcoal dust, so those times have been very few and far between. Maybe once in five or ten years?
The cats I've bathed at the shelter have either had ringworm or a massive flea infestation, or were very young kittens with diarrhea.
I have never intentionally bathed Sooty but he jumps in the shower with me and Flash is a bit more often than normal maybe 2 or 3 times a year she gets litter and stuffs caught in the back end of her fur, I only ever clean off back end though
otherwise I don't think I would need to they seem to keep themselves clean
I have 2 Cornish Rex one female and a male both fixed. These cats come almost hairless and due to that the "groming" instinct is almost gone. So that said I bathe them at least once a month. Not an easy task if you didn't start them young. Good luck