I was trying to look up "enchufla" as in the dance step. (yes, I did try without the l)
But so far I've been unable to find only three things:
- The history of the step, devoid of any etymology.
- The definition of the noun and verb "enchufe" and "enchafar" (regarding plugs and plugging), devoid of any etymology.
- Information of the propriety of "enchufe" versus "enchufle" for the plug noun. (Without the L is more standard, with the l is a regional variation.)
My best guess is that the step is named for the regional variation of the plug verb via an allusion/ figure of speech that's lost to time.
But I'd expect a decent Spanish etymological dictionary to cover enchafarplug, which makes it seem weird that none of google's results for "Diccionario etimológico" knows where it comes from.