Almost none of the orbital sweeping effect comes from collisions. Even Jupiter is tiny, in the scope of space. The majority of orbital sweeping comes from repeated gravitational deflection.
Having a tiny radius will reduce the amount of of collisions, but it won't have a significant impact on orbital clearing.
The comment mentioned "eating" specifically, where I felt collisions would be important. You're right that for clearing the size of the object isn't very important.
Having a tiny radius will reduce the amount of of collisions, but it won't have a significant impact on orbital clearing.