A naturalistic fallacy is simply appealing to "this is way it is before we do anything". Others have presented the counter-evidence - i.e. human hygiene and life-expectancy and disease rates got way better with the introduction of hand-washing and soap.
I'd think carefully about your anecdotal evidence. The social contract is we don't comment on matters of hygiene directly, and I know I couldn't smell how bad me and my schoolmates smelt after a couple of days field-trip out camping. That didn't mean we didn't.
I edited my response to clarify that I've had spontaneous compliments on how I smell, particularly since I switched. This is without people knowing I don't use soap.
And I thing hand-washing is good. We have clear evidence it works.
But is there any evidence that washing the whole body with soap on a daily basis is beneficial? The counter-evidence you speak of refers only to hand-washing.
Wikipedia distinguishes them, and that's in line with my understanding, although I don't know that my understanding wasn't derived at some point from Wikipedia or a descendent source.
As Wikipedia (and, apparently, G. E. Moore) would have us believe, the "naturalistic fallacy" is believing that you can reduce good/bad to natural states, and seems more closely related to Hume's "is-ought problem" than to the "appeal to nature". I actually think this comes down to disagreement about what is meant by "good/bad" more than substance, though.
Clearly, some do use "naturalistic fallacy" to mean "appeal to nature", and I'm not certain the original use of the term is worth preserving as distinct from Hume, but I'd encourage "appeal to nature" for clarity since that seems to have no ambiguity.
I'd think carefully about your anecdotal evidence. The social contract is we don't comment on matters of hygiene directly, and I know I couldn't smell how bad me and my schoolmates smelt after a couple of days field-trip out camping. That didn't mean we didn't.