A really great ambergris story can be found in Chandler Burr's excellent but slightly technical book The Emperor of Scent, see below. Mandatory reading if you have only a little bit of interest in the perfume industry and the way we smell stuff.
"The best Guy Robert story is this. The House of Dior started making perfumes in the 1940s. Very small scale. The first two, of which Diorama was one and Miss Dior the other, were made by Edmond Roudnitska, a Ukrainian émigré who'd studied with Ernest Beaux in Saint Petersburg because Beaux was the perfumer to the czars. So Dior approached Guy Robert-they invite him to dinner, they're talking over the cheese course, no sterile meeting rooms, this is a brief among gentlemen-and they said, 'We're doing a new perfume we want to call Dioressence, for women, but we want it very animalic. The slogan will be le parfum barbare, so-propose something to us.' Oh boy. Guy can hardly wait. Of course he wants a Dior commission. And the challenge of mixing the florals of the traditional Dior fragrances into an animal scent (because this isn't just any animalic, this is a Dior animalic, if you can imagine such a bizarre thing) is just a bewitching challenge, who else would have the guts to attempt joining those two. So he gets right to work, plunges in, and he tries all sorts of things. And he's getting nowhere. Nothing's working. He's frustrated, he doesn't like anything he's doing.
"In the middle of this, someone in the industry calls him, and they say, 'There's a guy with a huge lump of ambergris for sale in London-get up here and check it out for us.' Ambergris is the whale equivalent of a fur ball, all the undigested crap they have in their stomachs. The whale eats indigestible stuff, and every once in a while it belches a pack of it back up. It's mostly oily stuff, so it floats, and ambergris isn't considered any good unless it's floated around on the ocean for ten years or so. It starts out white and the sun creates the odorant properties by photochemistry, which means that it's become rancid, the molecules are breaking up, and you get an incredibly complex olfactory result. So Guy gets on a plane and flies up to see the dealer, and they bring out the chunk of ambergris. It looks like black butter. This chunk was about two feet square, thirty kilos or something. Huge. A brick like that can power Chanel's ambergris needs for twenty years. This chunk is worth a half million pounds.
"The way you test ambergris is to rub it with both hands and then rub your hands together and smell them. It's a very peculiar smell, marine, sealike, slightly sweet, and ultrasmooth. So there he is, he rubs his hands in this black oily mess and smells them, and it's terrific ambergris. He says, Great, sold. He goes to the bathroom to wash his hands 'cause he's got to get on an airplane. He picks up some little sliver of dirty soap that's lying around there and washes his hands. He leaves. He gets on the plane, and he's sitting there, and that's when he happens to smell his hands. The combination of the soap and ambergris has somehow created exactly the animalic Dior he's been desperately looking for. But what the hell does that soap smell like? He's got to have that goddamn piece of soap. The second he lands in France, he sprints to a phone, his heart pounding, and calls the dealer in England and says, 'Do exactly as I say: go to your bathroom, take the piece of soap that's in there, put it in an envelope, and mail it to me.' And the guy says, 'No problem.' And then he adds, 'By the way, that soap? You know, it was perfumed with some Miss Dior knockoff.'
"So Guy put them together, and got the commission, and made, literally, an animalic Dior. Dioressence was created from a cheap Miss Dior soap knockoff base, chypric, fruity aldehydic, plus a giant cube of rancid whale vomit. And it is one of the greatest perfumes ever made."