My Neighbor was getting rid of an old scratched up cutting board, made of thick beautiful wood. The upcycler in me immediately swooped up the prize and decided I'd sand it down back to new- but I didn't want to use regular sand paper on it since it's where I'll be cutting food and the chemical glues in crappy sand paper have never been declared food safe or gluten free (the stuff people with Celiac Sprue have to think of!). Not to mention sandpaper is one of those things that kinda rips us all off- you rub it around just a few times and the paper it's already shot, the sand is all gone, and your fingers are raw from pushing too hard.
So here's what ya need to sand it the old OLD school way (primitive, chem free, cheap, & EASY): A stone which has a flat side, sand, and your object of sanding desire.
Step One: Pour a handful of sand on the wood. Place the stone on top the sand.
Step Two: Start grinding ...not like on MTV The Grind- but by placing your hands over the stone and working the sand into circles. I found that you don't need alot of pressure if your stone has a good weight to it already. The stone itself will actually grind down the sand too, and make it very fine - so through the process it makes the surface of the wood smooth. The sound it makes is pretty awesome- it sounds like some sort of meditation didgeridoo monk chanting OM music.
NOTE: Stick something under the sanding project to catch the sand falling off the sides, so you can reuse that sand over and over.
LAST STEP: Once you are done with sanding buff the wood with just the stone and no sand, then wash the board off and check to make sure it's the consistency you like. Then heat up a little oil with salt and rub the board down to keep it protected. :) No more scratches, it's like brand new!!!!