it's hard but possible. I only had one at first..and it was so thin. It was naturally glued to the rock. I let it grew for a month or so, and then the duster was thicker, longer, so its radiole was 2 inches detached from the rock.
I carefully pulled a little, far away from the fan, so i wouldn't kill the worm.
If it splits in 2, well sometimes it isn't a big deal..it will grow back. The reproduction is by splitting. Anyways..so i pulled and everytime, i tried to reach its rear end. Finally i did it..only a little bit stayed on the rock...and it was unused parchment tube. I put it in the right corner of my tank, where my fishes where hanging..so it's was their feeding zone. My duster ate some of the uneated food..and grew...and grew. Now i have hundreds. With only one.
( what a beautiful story,hey?
)