No problem. Like I said if you are not using a spinner you will tear up your hands long before you grind the labels off a ball. That is the nice thing about surface management there is really no point of no return as you can always return a ball to nearly factory finish pretty easily. You do want to try and sand the ball evenly if you can because technically its against the USBC rules not to but would have to be obvious about it so don't stress. Also wet sandpaper or even wet scotch brites is actually how I sand the vast majority of my balls on my spinner so they are actually safer in that they keep the sanding more even and reduce wear on your sandpaper (in my case I use scotch brites and pads but same deal). I actually use Simple Green diluted with 5 parts water when I sand as it helps clean as well but completely optional. By hand don't usually need to wet the scotch brites. In general much easier to ruin a ball in your car trunk than with sandpaper. Still if you don't have a spinner I recommend getting a resurface from a pro shop after about 50 games or so. Its fine to scuff up a ball by hand with scotch brites to reapply the last surface desired but a proper resurface by hand is blister city (trust me).