A Witch Bottle Analyzed

From Fortean Times, an analysis of a witch bottle found in Greenwich, England in 2004:

It probably dates from the last quarter of the 17th century, and contained 12 bent iron nails (one of which pierced a small leather heart), eight brass pins, 10 adult fingernail pairings (not from a manual worker, but a person “of some social standing”), a quantity of hair and urine with traces of nicotine, indicating it had come from a smoker. There were also traces of sulphur, then known as brimstone, and what is thought to be navel fluff. The brimstone recalled the passage in Revelation where the beast and the false prophet were “cast alive into a lake of fire burning with brimstone”.

Navel fluff? That's a new one to me. And so weird that I have a sudden urge to write magical navel fluff into my novel.