As both a chemist, engineer and chef, I only use mineral oil or silicon grease for any food application. All natural oils break down and, depending on the application, can leave an off taste to the food in contact. Both are inexpensive and just good to keep it on hand.

I like the DIY concept. One can customize it to the type of smoking you do. I’m adding a small window A/C to have the ability to cold smoke as well. A small Honeywell controller allows for +/- 2 to 3 degrees. Can use most any box, old freezers, even a small wood structure.

The silicone will also keep the blades of grinders sharper and longer. I use it on all moving parts; blade, plate,and shaft and auger edges. I keep my wooden chopping boards coated with mineral oil. Does not promote bacteria growth and keeps the wood from drying out and splitting.

It does take time for the olive oil or any vegetable or animal base oil to oxidize and spol. Initially, those oils will not have a problem, it is only after some time and heat exposure will they begin to break down.
mineral oi or silicon grease will not break down with heat or time, so it is in the long run that they are superior.