Regarding your heat process do you just put it in the oven and bake it like you would to season a cast iron skillet or?
Oven on lowest temp would be good but I wouldn't use one that's going to cook food afterward.
I've tried a few ways. For little stuff I've cut a hole in a cardboard box and stuck a hairdryer thru. But usually just hit stuff lightly with a torch, keep it moving around.
Once surface is heated, then I apply the oil somewhat generously with a paper towel.
Let dry for 15, 20 minutes and wipe off excess.
Repeat everything one coat a day for 3, 4, 5... or more days.
The finish gets deeper and gains character as you add coats.
Burn your rag/towel fully after using or keep it submerged in water until it can be washed. The soaked rags have a funny little habit of self-igniting on rare occasions.
Haven't tried baking afterward (not sure if it's safe...?, probably fine) but I bet that would do nicely.