> Linseed oil is also used for many applications beyond oil paint, such as treating wood, to create a transparent, protective plastic barrier -- just as oil paint does, but this time, without color. Or for seasoning cast iron! https://www.cooksillustrated.com/how_tos/5820-the-ultimate-w...
And then before anyone runs with that suggestion, it's actually not a great way to season cast iron - it turns brittle and the seasoning will chip away (experienced this myself, and then did research).
A great place to start for seasoning cast iron is on reddit: https://www.reddit.com/r/castiron/comments/5rhq9n/the_rcasti...