I was talking about hygiene with my partner who is a nurse and they were telling me that a lot of people remark that their armpits are smelling worse than normal and they are using more and more deodorant and people just think it is normal.
Trichobacteriosis looks like a yellowish coating on some of your armpit or groin hair and you need to shave and wash the area every day for 2 weeks. It is more common in men than women in the US only because it is more common for women to keep their armpits shaved. Most of the patients who are affected by it think that its actually residue from the increasing amounts of deodorant they end up using.
In other words, you make sure you clean your body well.
Edit: but to add to your point, what I do is wash my armpits, then smell them. Is there still a teeny tiny smell left? Rinse and repeat. As many times as needed. Three, four even five times. Until they smell undoubtedly clean.