Until we can control the microbiomes at will whe trick is that it's very hard to tell if you are one of the people who won't smell bad if you skip the soap and deodorant, or if you're one of the people who will. Especially if you're single. :)

Personally I've found I don't need a ton of soap, can get by without deodorant if not especially active, and can skip shampoo most days but do need conditioner and aggressive rubbing it in/scalp self-massage to avoid dandruff.