Usuba Dashi - you totally busted me, I have not oiled it in quite some time. I did the salt and lemon as recommended and I added in the baking soda for good measure. I did it twice and let it sit for 1.5 hours each time. It is vastly improved - thanks!

Once you have cleaned it and fully dried the cutting board, you must seal it with either mineral oil or walnut oil. Any other oil will go rancid, so use only those two. Lightly sand the surface first then apply oil and allow to absorb in a warm area. Do this every 6 months or so. By sealing the wood, you will have less problems with odors.

I cut anything too aeromatic on a paper plate on my plastic cutting board. Even if I chop directly, I always clean the cutting board with white vinegar to help remove any oils, then scrub with baking soda using a medium scrub brush I keep for kitchenware cleaning. It does the trick for me.

I think this also suggests that wood can present sanitary problems for food preparation. The USDA recommends cleaning a plastic or wood cutting board with: a solution of 1 tablespoon of unscented, liquid chlorine bleach per gallon of water. Flood the surface with the bleach solution and allow it to stand for several minutes. Rinse with clear water and air dry or pat dry with clean paper towels. More at:
http://www.fsis.usda.gov/factsheets/Cutting_Boards_and_Food_Safety/index.asp

I buy enzyme cleaner from my grocery store and it's amazing at eliminating odors & stains. Safe for your cutting board. The enzymes attack pet, food, beverage and other organic compounds. Really amazing stuff. This brand is great, but any enzyme product should work. I use this product to basically clean my entire home. http://www.amazon.com/Bi-Kleen-Bac-Out-Eliminator-Cultures/dp/B000IAEVXE

What kayb mentions is what should be a standard practice on a continued basis not just for oders but maintaining a healthy/sanitary cutting board.

I like Kayb's idea of letting it sit. I like to rub the board with half a lemon, then sprinkle some salt on the board and start scrubbing using the cut side of lemon half like a sponge. I give the lemon a good squeeze now and then to release more juice. The salt has a scouring texture, so if it dissolves while sitting I'd add a little more . . .

Make a paste of salt and lemon juice, spread that on it, and let it sit for an hour or so; then rinse it off. A paste of baking soda and water might work, but I know the lemon juice/salt combo will.