You won't find people on lemmy who will admit it.
I do know a semi(?)-homeless person who stinks so much I buy air freshener just for when he comes by.
He is a crystal addict, pothead and mentally ill. His mental development is about 14 year old. Very sweet guy.
I believe he is living in a house, but who knows his stories doesn't make sense. He doesn't even have a name because 'they have to gove it to him'.
I don't know if he has a place to shower, but I don't think he has a mind to think of showering. He has several changes of clothes and once.
I believe body odor is a defense mechanism also - you are less likely to get raped if you stink like ... Everything.

If a healthy not addicted person stinks - there are reasons and most of the time it is mental illness or homelessness.
(Except for outliners back to nature and so on)