What was most amazing watching Grease create was it truly was, literally, stream of consciousness/out of the blue. He used to do live, unscripted on air ads for a jeweler in DC named Ronnie Mervis, who's family came from Africa. He set it up, did all the voice work, sfx, etc. You can just imagine what those ads sounded like. Hysterical.
I actually think that the syndication hurt Grease, because in the "old days" i.e. on DC 101 in Washington, he combined the bits with localism/calls from listeners that he'd react to. That got lost in syndication, so the bits became predictable. Also, they tended to peter out, as opposed to having a laugh-out-loud punchline. Finally, Grease was sorta stuck (no pun intended) in the old days; the bits weren't updated at all. For example, Sgt. Fury was STILL in Vietnam in 1995...maybe he coulda updated him to be in Iraq during Desert Storm? But he didn't want to hear that feedback. The result was that the show felt older than it should.
All that being said, he was a great guy to work with, super nice and cooperative for the most part.