I have offered plenty of advice on caring for your cast iron cookware. Stop seasoning it in the house, use your BBQ.
Seasoning this stuff in the oven (my favorite old way,) or on the stove smokes your house up. Just throw the shit on the grill.
Super thinly put a coat of oil on your cast iron piece.
Put the cast iron piece on the grill.
Heat the grill up, let it run until the cast iron piece has stopped smoking.
Turn off grill and let cool down.
Repeat.
I was able to perfectly season a set of cast iron Pie Irons with no problem.