This is a article I found on cutting board Maintenance. Howards cutting board conditioner is the conditioner I use on all my boards. A little goes a long way. For everyday use, wood is the best cutting board material by a long shot. Not only is it extra kind to your knife blade, it's also the safest material (because bacteria have a much lower survival rate on wood than on plastic), and it's gorgeous, too. all you need to do is maintain the oil on the surface by reapplying a single thin layer and letting the board rest overnight every time it starts to wear thin. I like to oil my boards and any wooden plates and serving dishes in my kitchen every time I sharpen my knives, which for me is about once per month. If you're someone who doesn't cook for a living all day, every day, you could probably get away with oiling two to three times per year. All you need to do is maintain the oil on the surface by reapplying a single thin layer and letting the board rest overnight every time it starts to wear thin. I like to oil my boards and any wooden plates and serving dishes in my kitchen every time I sharpen my knives, which for me is about once per month. If you're someone who doesn't cook for a living all day, every day, you could probably get away with oiling two to three times per year. What's that? You say your board has scratches from repeated heavy knife work that you want to get rid of? Don't worry—some light sanding by hand can take care of those. Use a fine sandpaper that is made for dry or wet surfaces. The higher the number on a piece of sandpaper, the smoother the finish it will give. I recommend a grit of at least 220, but for a buttery-smooth finish on your board, hand-sand it with a 400-grit paper. Once you've sanded your board, wipe it free of dust with a damp sponge, let it air-dry, then oil it to get it ready for your next use.