The char and ash produced by the laser are no different than any other combustion product. Everything should get a good scrubbing at a minimum. I then give them a couple of coats of food-grade mineral oil (aka cutting board conditioner), repeating every few months.
As with anything with nooks and crannies, critters can hide out and live on bits of food caught in there, but an occasional scrub with a bleach based soap will eat whatever is hiding out there and the oil will restore the wood