===Machine oil===
Machine oil is a thin light petrolum oil used for undemanding
lubrication, such as small machinery, hand tools etc. It is also
widely used to thinly coat steel tools before export, preventing rust.

Sewing machines and many other appliances use machine oil.

Baby oil is machine oil with a little mild perfume added, and this is
a very convenient way to buy machine oil for many DIYers. (The method
of its extraction from babies remains a closely guarded secret.)


Baby oil / liquid paraffin / white oil for medicinal use are very highly
refined.

Machine oil is a very loose term, it may refer to "edible oils" as use on
bacon
slicing machines, etc, but it may not. I would expect sewing machine oil to
contain various additives, some of which you might not want to put on
babies.

For "domestic" use I certainly wouldn't use medicinal oil for rust
prevention,
I'd use 3 in 1.