Several people on here use linseed oil. I have not used it on hives but have used it on wood over the years. I think it works fine, and the cost is no more than and probably less than paint.
I have just not painted them at all. I've also used the latex paint base with no pigment.
One thing to watch for with linseed oil is if you get it on rags it will get hot and catch fire. I've never seen this happen with motor oil or other oils, so I'm sure there is a chemical reaction with the celulose in the rag. Be sure not to put linseed oil soaked rags anywhere where they will catch something else on fire.
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