Troof: Most people wash too much.

Plain water is good enough most of the time. Soap and shampoo strip out oil from your skin/scalp leading to dermatitis, dandruff, dry, flaking skin, etc. So then people apply manufactured products that replace what they just stripped off.

BO is bacteria and/or fear/stress hormones and/or sexual attractants. The bacteria issue is solved by using freshly laundered towels to dry with and wearing clean clothes. This solves at least 90% of BO problems.

The stress secretions can be more of an issue. If I'm going to a psychologically stressful activity I'll use more surfactants, but if I'm just sitting in the office, plain water washing followed by a splash of 70% isopropanol (aftershave, pits, nutsack) works. No one ever comments on any odor. Women like the way I smell, which is pretty much no smell at all.

Daily: fresh water shower and hair rinse.

Approx. twice a week: soap and shampoo.

Some people's physiology produces more of the odor-producing secretions. I guess I'm lucky.