I used a generic one once on a customer's white quilt. Tiny specks of black came out of it. I am guessing it was some kind of lubricant. I called the company and they were no help. I ordered another from someone else. Same thing happened. This time I called the company and they were very apologetic but what could they do? One girl did try to offer some cleaning tips. It was a nightmare. I have never used one again and do just fine without it.