What does it mean to “season the rim” of a Dutch oven/slow cooker?
The directions say - "Although the enamel coating on your cookware does not require seasoning, we recommend seasoning the vessel rim and lid rim where the cast iron is exposed with cooking oil. Heat your cookware in oven at 350 degrees for one hour".
Is it telling me to rub oil (not sure what is best) on the rims and then cook it by itself in the oven?
Rub cooking oil on it and let it back in the over about 40 minutes.
If possible, let sit over night.
You have to dpo the same with cast iron skillets, too.
There are sites for this as well.