I didn't think offering such a simple and harmless advice would lead to being picked clean, But i am willing to continue peacefully. and hopefully someone learns something in the end. this is my personal opinion and how i do it, no one has to join me unless they see it worthwhile.
First off before we go any further, i think its safe to say that the method of preservation for a cooking board depends on a few things. They might be what the board is used for. Is it general use? only for dough? meat only? veg only? no knives, etc.... and of course the type of cutting board and the wood used in its production. A board used to hack dead animal parts with a heavy cleaver needs much different care than a one used only for bread dough. make it end grain or not and that changes things too. we could argue for years talking about how one thing works for one situation but not the others.
Listeria and Clostridium as your examples don't really prefer the type of environment a cutting board properly washed and cared for likes. the environment of a sealed or semi sealed pickling container are much different than a open air board. the salt has different effects on each. salt and desiccation are not bacteria or pathogen friendly places usually. your point of pathogens potentially living in some salty environments is valid. i didn't mean to assume nothing bad can ever grow in a salty place, just the boards surface.
i honestly don't measure my brine accurately by percent for the wooden boards, usually a cup for a gallon of water which gives me somewhere around 7% brine. to me its just a regular thing, not rocket science. I do have boards for different uses, some don't even get the brine like my dough table. it gets just the oil.
no where did i say wood is antibacterial. those are your words.
as for the dulling of the knife on certain woods, everyone should be sharpening their knives regularly anyways imo. but once again that's my personal opinion and not for this topic.