Actually, I was referring to there being no padding possibly making it too intense to roll on.
However, that's interesting...I didn't think about there not being enough friction with bare PVC to work well...
After giving it some thought...you could try rubber spray coating it with areosol Plasti-Dip. http://www.plastidip.com/home_solutions/Plasti_Dip.
It would probably need about 3-4 coats which I would estimate at probably 2 cans worth.