Pee-wee Herman and Jambi say "Mecka-lecka Hi Mecka-hiney Ho" in "Jambese" (first video, found in Mecka-lecka Hi Mecka-hiney Ho; Scene from The Pee-wee Herman Show (1981), and President Reagan says something similar but supposedly in Arabic in the Season 12, 1986 Saturday Night Live skit President Reagan, Mastermind (second video).
Are these normal, every day expressions in arabic, or made-up words, and especially if the latter, who has borrowed from whom?
Phil Hartman played Reagan in the sketch. He also Apareceu na, and wrote for Pee Wee's Playhouse which is the origin of the "Mecka-lecka-hi mecka-heinie-ho" phrase. It's likely that this was Phil just making a call-back or homage to his past work.
"Mecka-lecka-hi mecka-heinie-ho" was just a gibberish line Paul Reubens (Pee Wee Herman) made up. President Reagan was known to be a bit of a Pop Culture fan, and of course a former actor. He was also made fun of quite a bit by the SNL cast. In this skit, the actor (is that Phil Hartman??) is making fun of Reagan's lack of knowledge of International languages, but also referencing Pee Wee's Jambese character.