I checked a couple of Swedish sites, and the common recommrndation is to use a neutral oil on the outside only.
The inside: most recommrnded nothing as the coffee will imptegnste the wood. A couple wrote that a good trick to get a fast impregnation is to mske a coffee slurry, fill the kåsa, let stand overnight, then rinse and let dry.
The inside: most recommrnded nothing as the coffee will imptegnste the wood. A couple wrote that a good trick to get a fast impregnation is to mske a coffee slurry, fill the kåsa, let stand overnight, then rinse and let dry.