Here is a good tutorial: https://www.todayshomeowner.com/how-to-clean-and-oil-butcher-block-for-use-in-the-kitchen/

Food grade mineral oil --- never use water or abrasive materials; when finished using it -- for meat/veggies/fruit, whatever -- wipe with hydrogen peroxide on paper towels ... dry, and apply the food grade mineral oil --- Amazon or any good kitchen supply store ... https://www.foodnetwork.com/how-to/packages/help-around-the-kitchen/photos/how-to-clean-a-wooden-cutting-board

I'd first sand the cutting board, using progressively higher grit sandpaper to get it smooth and back to near its original color. A food grade oil is the most recommended thing to use on finishing off a cutting board.

Sand it smooth and rub on a couple coats of Tung Oil.

The way I do mine, and they're butcher blocks, is to scrape the entire surface, with the grain, using the back of a large knife to get all the old gunk off. Then, wipe it clean and use only MINERAL OIL! Don't use olive or any vegetable oils! They'll turn rancid. I have a large one, which was the top of my portable dishwasher from the early 1960s, and it's still in great shape!

Differences in protection http://www.snwwood.com/Blog/Butcher-Block/What-is-the-best-finish-to-use-for-butcher-block-countertops

So what is better for a wood cutting block? Tung oil or Mineral oil?

Here is what I just did for ours- https://www.hometalk.com/44298420/how-to-restore-and-maintain-a-wood-chopping-block

How to Restore and Maintain a Wood Chopping Block