Is roloc abrasive available in an elongated cylinder / tube shape?
Roloc is primarily an attachment system for quick-change of abrasive pads/discs. 

The (usual) abrasive material attached to those mounts is "non-woven abrasive" (which you might know a specific example of by the trademarked brand-name Scotch-Brite®.) It comes in many grades/grits as with most abrasive products. They are commonly color-coded, but color codes may not be consistent across different manufacturers.

Searching for "non-woven abrasive drum" (as in drum sander) or "non-woven abrasive flap-wheel" may yield results that will function as you want, but they won't click into a Roloc mount, as far as I'm aware (I've never seen one that does, anyway.)

I did happen across "Roloc Bristle Discs" when researching this answer, which might work for some applications.