My first build GST-1

[McCreed]

Not sure what you mean by 'mineral oil' as that covers a wide range of hydrocarbon oils.

I'm pretty sure he's referring to plain old mineral oil that you would pick up at the chemist or hardware store.
You can buy "food grade" mineral oil, but it cost way more than the bog standard stuff and is completely unnecessary for a fretboard.

FWIW, when you buy "lemon oil" for your guitar, you are literally getting lemon-scented mineral oil at an inflated price.
If you want your fretboard to smell lemony, a few drops of essential oil of lemon into a small bottle of mineral oil and you've got the same thing for a fraction of the price. You can also use straight unscented mineral oil just as effectively.

I have a bottle of an Aussie product called O-Cedar. It's a furniture polish, and guess what the main ingredient is? Mineral oil.

I think it's a 150ml bottle. I have had it for at least 15 years and at the rate I've used it, it will still be over half full by the time I'm dead and buried.

[TonyV]

I'm pretty sure he's referring to plain old mineral oil

Hi McCreed, you are correct. I have a bottle of white mineral oil that I've been using on wood products for a while, and it is lasting forever. I used it on the fretboard of my son's Strat when I was cleaning it up and it really made it pop.

https://www.ikea.com/au/en/p/skydd-w...-use-00170993/

I guess I would like to know if this is safe and appropriate to use on a raw Jatoba fretboard? Or whether I need to source something else.