foggytown asks:

But I have a continuing problem I can't solve.

Can anyone recommend a sealer/stain/paint/varnish/shellac/whatever
that can be used on the INTERIOR of wooden containers made to hold
food? (Like cannisters, bread bins, larders, etc.) It should be a
hard gloss finish (for easy cleaning) and has to be completely
odor-free and non-toxic so no taste or odor transfers to the food
inside.

Is lining the item with plastic or something similar the only answer?

For the most part, it pays to line wooden food containers with a flavor free
wood, yellow poplar, basswood, sycamore, popple (cottonwood), etc.

Even that will get smelly if food is left sitting inside too long, but usually
a wipedown and a day or two food free with some baking soda inside will clear
things up.

Otherwise, plastic or glass liners do work.

Charlie Self
"When we are planning for posterity, we ought to remember that virtue is not
hereditary." Thomas Paine