I have made the bowls and coasters but never thought of a rug.
Okay another project in my mind to do.
When I make the bowls, I use a small black spring paper clip.
They hold tighter than a clothes pin and won't come off if you put it aside for a while. I also use a denim needle.
** Also, to the lady that wondered about how much goes under the neck of the machine...you work from the inside out and so you would only have the round you are sewing on under the machine neck. Hope this helps :)