After extensive searching, I am unable to find much or anything in the way of people using wood type finishes on unglazed fired pottery, in place of refiring with glazes.
For example(s), terracotta or possibly even raku +
* polyurethane coats
* drying oils like linseed
* for a different coloration and look, something like a drying oil combined with limewash
Obviously none of that is appropriate for, say, oven use, but for tableware, why not? Coming from more of a woodworking background, these things seem straightforward and intuitive, but the lack of any actual examples of them I can find gives me pause.