Reply by ChefHDAN

As long as nobody is going to use a knife directly on the surface, you’re fine to go with any type of finish for a non-food contact surface. My experience is 99.9% all food contact surfaces, but did once use WB poly for a display platter that was going to be used for passing cold appetizers. It held up well for several events until a “new” dishwasher put them through the machine…. If I were in your position, given how much my teenage kids throw the water around when doing the dishes, I’d look at some of the marine grade finishes and seal all 6 sides of the counter.

-- I've decided 1 mistake is really 2 opportunities to learn.. learn how to fix it... and learn how to not repeat it