I generally use coconut oil due to its high smoke point or home rendered lard for all cast iron cooking. You could use bacon grease in a pinch.
Here’s my honest suggestion and what I do to get my pans seasoned:
Cook a small batch of bacon, coat the entire pan with the remaining, and let it cool completely. Repeat 3x
Otherwise next time wife cooks in oven, put the pan in the bottom and take it out when its too hot to touch and wipe with coconut oil, then let it cool completely. Repeat 3x