Equivalent of "That said, Carthage must be destroyed" in Japanese

Question

"Ceterum censeo, Carthaginem esse delendam," the famous phrase with which Cato the Elder used to finish all of his speeches, no matter how unrelated the topic was. It was probably an effective strategy - as another well-known political figure put it, "Repeat the most ridiculous thing a thousand times, and people will start to seriously consider it."

In modern English, its usage is humorous, with irony directed at yourself as you admit you are relentlessly nagging somebody about something you (selfishly) believe they should do. Is there something similar in Japanese?

Since the historical background is completely different, I would imagine that it does not carry over directly. Even though, for example, Wikipedia has an article explaining 「カルタゴ滅ぶべし」, it is probably purely academic, not something you could use in a conversation and be readily understood? Imagine you are finishing each and every email to your friend with "That said, you should dye your hair pink." To a Westerner/English speaker, the reference is obvious. How would you go about expressing the same nuance in Japanese?

Answer 1

I assume you are looking for a Japanese equivalent of "ceterum censeo" and are not looking for an equivalent of "Carthaginem esse delendam" (or "Cartago delenda est" if sticking to the indicative.)

My answer is: there is something remotely resembles to that expression, but the usage is different (not that "serious," I would say.) It goes like 「それにつけても金の欲しさよ」 which means "That said, I want money."