I picked up the CRBN Paddle Eraser to deal with the ball fibers that build up on my carbon-faced paddle, and it does the job. After a few swipes the grooves look noticeably cleaner and the surface feels grippier, so my spin is back to where it was when the paddle was new. It's small (2x2x1 inches, 1.5 oz) and easy to keep in my bag. Doesn't restore a worn-out face, but for routine upkeep it's a handy, simple tool worth having.