[Tony B]

Most people that I know that have purchased artsy type cutting boards would never actually cut on them. They bought them for their decorative value.
if your boards are meant to be decoraive, then you can use any type of finish you want - preferably something that looks good. Sell them with the understanding that they are purely decorative and not meant to actually be used.

You can always scribe into the underside " for Decorative use only".

 

[Tony B]

I normally work with exotic woods. Sometimes i will go to sawmills for good slabs for table tops and for turning. One time i purchased several boards of mesquite for a coffee table. I remember it as a very dense close grained wood. But thats from memory only. Mainly remember it as the wood I will never again work with. It was beautiful but it wore me and my tools out. Like I said, It is beautiful but way to hard and dense to be worth the effort. Especially when you are on an hourly rate in your own business.
Anyway, I just ran a few searches on mesquite and they also said it was a close grain very dense wood. More dense that hard maple.
I would guess that mesquite is not real common in cutting boards or most other wood products partially because of its difficulty in working properties and mainly because mesquite is not widely available outside of the southwest and Mexico. Also not much harvesting of mesquite for a building medium because the trunks are generally not that big in diameter or height.
Anyway, just thought I would throw that in.