Has anyone used this?

I think it's intended to be used before putting a CI pan away after cleaning.

Sealer/Rust inhibitor?

Looks like they are marketing spray-able oil to me and probably charging extra.

Sealer/Rust inhibitor?

IDK.  Many of us give our CI an extremely light oiling before we put it away.  I thought maybe this is intended for that.

lard

My wife scrubs ours with hot water then dries it then puts either avocado oil or coconut oil on it while it is still warm.  If you fry bacon in it that is really good for it. Do not use soap & water. Just hot water. You have to season it before first use. My wife loves ours and won’t fry with anything else.
Z

My wife scrubs ours with hot water then dries it then puts either avocado oil or coconut oil on it while it is still warm.  If you fry bacon in it that is really good for it. Do not use soap & water. Just hot water. You have to season it before first use. My wife loves ours and won’t fry with anything else.
Z

You married a very smart woman!