Here is how I Clean & Season Cast Iron, which works well.
I wish I could remember where I read it to give them credit.
Set Oven to 325
Clean:- Scrub with soap and water
- Rinse well
- Put in oven 5 minutes to dry
- Scrub with mixture of salt and water
- Rinse with Water
- Rinse and scrub with vinegar and water, 1 cup vinegar and 1 quart water
- Rinse well with water
- Put in oven, dry 5 minutes
Season:- Wipe with canola, or olive oil(shortening or bacon grease good), corn oil(sticky though)
- Put in oven upside down & line underneath with foil
- Bake 1 hour, let rest & cool down in oven if possible