Knowing that water and electricity do not mix well I used a palm sander with wet 80 grit (and latter 150 grit) sandpaper and a spray bottle of water to control the volume and application area of water. It was messy but worked well and the water did not get on the electrical portion of the sander. Wet sanding by hand is not hard. The water keeps the paper from plugging up and it continues to cut well. It's rather a satisfying process.

It is sometimes difficult to find a coarser wet/dry sandpaper but look at paint stores and body shops. Wet sanding goes pretty fast so you should not have to invest too many hours to get a fresh surface to refinish. Earl