To care for and clean a good quality wooden board (i.e., an end grain 2 inch thick hard maple board), the steps you should take are as follows:
A. a straight-edged metal scraper, preferably with rounded ends.
B. a spray bottle filled with full strength clear vinegar.
INSPECTION AND TREATMENT BEFORE USE
1. Upon receipt of the board, check for flaws (glue failure, gouges or nicks in the board, gaps, etc.). If you find them, reject the board.
2. If Step 1 checks out OK, then treat your board to multiple layers of mineral oil. Don't just do it once - do it multiple times until the board starts begging you to stop (Okay, that means that no more oil gets absorbed).
3. From time to time, repeat Step 2.
4. Each and every time after you have used the board, first scrape the board surface clean. Then clean the scraper with hot soapy water.
5. Then hand wash the surface of the board with hot, soapy water and rinse with hot clean water. DO NOT IMMERSE THE BOARD IN STANDING WATER!!! Then scrape the board with the (now clean) scraper.
6. Now spray the full surface of the board with vinegar. Do not wipe the vinegar off.
7. Set the board up so that it will air dry.
That's it. Saturating the board with mineral oil is the first step to ensuring the board will not absorb water and expand. Scraping the board will remove the majority of surface gunk and water. Soapy hot water will emulsify any remaining oils (which are the binding agents for pathogens) while the hot clean water will rinse that hot soapy water (and emulsified oils) away. The (cleaned) scraper will remove a significant portion of residual water clinging to the board. And vinegar is an antiseptic, which will kill pathogens, then safely decompose in exposure to air (provided it is not wiped off the board right after application).
And your end grain wooden board will be soon ready to be cut/chopped on again.