Something that has been working for me seems too easy to be true, but I have done it several times with good luck.
Get your charcoal grill fired up, don't use too much charcoal or you will burn the seasoning right off! A small pile will do.
Then apply either Pam or Crisco. Close the lid! I just forget about it, and when it is completely cool, go get your CI.
A little experimentation is necessary, if it doesn't burn long enough, the surface will be sticky, but it doesn't smoke up the kitchen and is really easy.