Some woods are ok but dont know about cocobolo, best bet is to look at what tobacco pipemakers use for their pipes, briar is traditional, think you can use ebony. I have made a pipe from olivewood before. I got some sapele i might try.
You probably know about this as a woodworker but its useful for anyone else. Toxic Wood List---
https://www.wood-database.com/wood-articles/wood-allergies-and-toxicity/
its not completely comprehensive but theres a good amount of info.
Issue with woods is some people react more than others, and you probably know about sensitizers vs ones that react more immediatley if they dont like you. Wood toxicity is mainly a dust issue, but can also be a contact issue for some.
if only a quick spritz of nitro laquer would work, could add to the effects of the herb.........(if you are laughing at that you know.... if not DONT USE NITROCELLULOSE LAQUER OR ANYTHING SIMILAR)
I think some woods can be sealed by charring, possibly you could work liquid reclaim hot off a 'boro bowl into the wood inside the bowl, but I would be wary of using anything else,maybe coconut oil as it has a high temp smoke point, but any food oil will go rancid over time. Mineral oil(same as baby oil not car oil) possibly, but not sure its exactly foodsafe. Maybe beeswax worked in then cured .
I would cure the bowls no matter what, maybe pre char them , but a long reasonable temp cure should vapourise most of the surface oils in the wood.
Also warn people that purchase them that some individuals may have an allergic reaction to certain woods.
To save your lungswhile curing it, and for hygene if its for sale, Get your sturdiest Straight bong, put the bowl in the bong without a downstem or any water, attach a hoover on low power to the mouthpiece and put a hot injector head backwards against the bowl and turn the hoover on.
I havnt tried it yet but intend too. Be careful with your glassware if you do. let me know how it goes if you try it?