So I was going to say Mr Sparkle isn't actually in this episode but there is a quick reference, but no actual Sparkle.

In the episode "In Marge We Trust", where we learn Homer aka Fish-Bulb is Mr. Sparkle, we have a commercial featuring a man interviewing a two headed cow,

In this specific episode "Thirty Minutes Over Tokyo", during a commercial break after the seizure robots we briefly see a similar scene with a different colored cow,

So still a reference, but no actual Mr. Sparkle.