nope - the origin of this is known -

Al Capp took whammy and used it in his comic strip Lil'
    Abner, first in July of 1951:

          Evil-Eye Fleegle is th' name, an' th' "whammy" is
          my game. Mudder Nature endowed me wit' eyes which
          can putrefy citizens t' th' spot!...There is th' "single
          whammy." That, friend, is th' full, pure power o' one o'
          my evil eyes! It's dynamite, friend, an' I do not t'row
          it around lightly!...And lastly - th' "double
          whammy" - namely, th' full power o' both eyes -
          which I hopes I never hafta use.

"wham" was a blow, strike,

Al's use of whammy and double whammy are the first recorded.