I was thinking of the old tale titled "the emperor wears no clothes", which inspired an amusing train of thought.
We could build a "stealth" wall, and just have Mexican mimes pantomime its existence.
It would be a hell of a lot cheaper, and my parents could start earning a fucking pay check again.
100,000 stink bombs, and 100 real mines. Minimal international incidents, plus the government could video the results and monetize them on youtube to start paying down the debt.