I use these for a light sanding:
CUE REPAIR ARBOR TOOLS (SET) CLEAN SAND TAPER CUE TIPS lathe pool billiards | eBay Just lock the drill motor down snuggly in a vice. I sand with the left hand while maintaining a light grip/support on the ferrule with my right hand. They work great. Done many. Never even came close to messing up any of my shafts (yes, even my 314's and my OB Classic).
And yes....if you do some research, you can find them one per package:
CUE REPAIR ARBOR TOOL 3/8 x 10 SHAPE TIPS SHAFT CLEANING SANDING pool cue lathe | eBay
Of course I've never set out to sand a shaft to a smaller diameter, just a light sanding to remove any burrs that occasionally rear their ugly heads. I start out with a 600 or 800 grit, then graduate to a 1000 grit and finish of with a 2000 grit and then burnish with a piece of leather. My shafts are slicker-than-owl-shit. If I feel the need to remove some wood, I'll use a 400 grit. IMHO, 200 grit is a very aggressive sandpaper to start out with (unless you're in a huge hurry).
Love these little tools though.