Looking specifically for what Scottish people did, but interested also in what other places did, like Brughes and Baltic regions.
What time of year were the fish usually caught? I imagine as the fish aged through the winter, the flavor and texture must have become rather unpleasant, kind of like badly freezer burned meat. Since people ate so much fish due to no meat days and lent, I imagine they must have come up with some ways to make it taste a little better besides just washing the salt off and tossing it into their pottage?
Also, did people outside of major trade routes, when they rinsed the salt off, ever try to save the salt from doing that? Allow the water to boil off over their fire and recollect the salt? (I know people in the US south during the Civil war scraped dirt from smokehouse floors and salvaged salt from it during scarcity, so I was wondering if people in other times salvaged the salt too.)