It was an urban legend years before the alleged 1981 origin
I was able to find some snippets and they mostly throw doubt on it being a real Napoleon quote, not least because it's been attributed to so many other people. (There's no evidence that any of them said it either!) Because they come from Google Books, I can't be certain that the years are accurate, though I tried to verify each one by searching for other years.
L'Entente du couple, 1970:
«J'arrive, ne te lave pas...» écrivait Napoléon à Joséphine. Je pense souvent à ce cri de sensualité lorsque je vois ces affiches publicitaires invitant à bannir toute odeur corporelle et à transformer tout corps en fraîche salade.
Translation via Google:
"I'm coming, don't wash..." wrote Napoleon to Josephine. I often think of this cry of sensuality when I see these advertising posters inviting to banish all body odor and to transform any body into a fresh salad.
Des Français: roman, 1970:
...heureuse de briller par un détail qu'elle tenait de Francis, dit que cette négligence avait peut - être un fond aristocratique, puisque Henri IV écrivait à sa maîtresse: «Ne te lave pas, j'arrive.» Ce roi prétendait, du reste, qu'un bon gentilhomme doit avoir «les pieds fumants et l'aisselle suète».
Translation via Google:
...happy to shine by a detail she had learned from Francis, said that this negligence had perhaps an aristocratic background, since Henri IV wrote to his mistress: "Don't wash yourself, I'm coming." This king claimed, moreover, that a good gentleman should have "steaming feet and sweaty armpits."
Skin Health and Beauty, 1969:
Baudelaire, who had been vacationing in the south of France, upon deciding to return to Paris telegraphed his mistress, “Ne te lave pas. J'arrive demain.” (Don't wash. I'm coming home tomorrow.)
An American Romance: The Alan Poems, a Journal, 1969:
Was it Baudelaire, to his mistress, sent the wire 'Due back in Paris in three days; don't wash'?
Before that, nothing
For something that was allegedly said by several famous people who died over a hundred years prior, there is no trail in Google Books dating back any further than that. It's not in Les lettres ardentes de Napoléon à Joséphine or Napoleon's Letters to Josephine. The latter, however, has some other quotes by Napoleon about baths:
- Corvisart tells me that it is a good sign that the baths are having the desired effect, and that your health will soon be re-established.
- You say nothing of your health nor of the effect of the baths
- Advise me by the courier what you intend to do, and how soon you expect to end your baths.
With this explanatory text:
The waters.—Mlle. d'Avrillon describes them and their effect—the sulphur baths giving erysipelas to people in poor health. Corvisart had accompanied the Empress, to superintend their effect, which was as usual nil.