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.
The conditioner helps with styling it / keeping it feeling smooth and pliable. Especially since I still shampoo once or twice a week for additional dandruff control, which wipes out some of the natural oils.
The aggressive rubbing is the part that does the daily dandruff control. Seems to exfoliate the dead skin.
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.