Mineral oil is also used medically as a laxative; you put a few spoonfuls in a glass of juice and drink it. So, pretty safe to use as a wood conditioner but its

Mineral oil is also used medically as a laxative; you put a few spoonfuls in a glass of juice and drink it. So, pretty safe to use as a wood conditioner but its not a drying oil so needs to be re-applied from time to time. It's used a lot on wood cutting boards, which take a lot of abuse and need regular re-application of a flowing finish that won't build up in hard layers. Wax can be used over most wood finishes to to give it added lustre but also needs to be re-applied to maintain it. The advantage of a drying oil is that it gets absorbed deeply into the pores of the wood grain and dries to a plastic-like hardness. Because the unpolymerized oil penetrates so deeply, the cured finish isn't just a hard layer weakly bonded to the wood surface which can flake off, but weaves itself into the grain and pores of the wood itself. It seems that most people who avoid linseed oil finish complain they don't like the smell when working with it. Walnut oil can be dangerous for anyone who has peanut allergies, which might be one reason why its not so common.