Back in the day, I worked in a meat department of a grocery store and cleaning the butcher block was one of my duties at the end of the day. This thing was huge and weighed several hundred pounds and well worn on top from use over the years. Standard procedure was rinse with a garden hose, dump a lot of kosher salt on the top, and brush vigorously with a wire brush. After rinsing again, that was pretty much it.
I guess the butcher block counter tops are a little industrial for most people but I like them and would love to have one.