I don't suppose it was... to ferret? Reads article Yes. TL;DR to pull string through the whole thing so they could clean out little metal shavings using a mo

I don't suppose it was... to ferret? Reads article Yes. TL;DR to pull string through the whole thing so they could clean out little metal shavings using a mop or foam or whatever attached to the other end of the string, which they'd pull through after the ferret. So it was driving out—or ferreting—the metal shavings.