Oil will seal it temporarily you will need to oil it aleast twice a year

We would recommend oiling the top monthly to prevent it from drying out, but it will allow you to cut directly on the wood without damaging the finish. You can either use a permanent finish around the sink, or just apply oil more frequently around the areas that are exposed to water.

Mineral oil, won't turn rancid and is food safe. Very easy to apply. Once a month is a good idea. I do this with my cutting boards.