"Smithereens"

The American Heritage dictionary gives the following etymology:
From Irish Gaelic smidirīn, diminutive of smiodar, small fragment.

The OED is less certain: "either adopted from, or the source of, mod.Ir. smidirín"

the source of, mod.Ir. smidirín"

With this possibility and the OED inclusion of "smash" in the definition of "smithereen", could smithereens be the little bits of slag and metal (sparks) which often accompany a smith's hammering?

Can one try to work metal when it is too hot (almost liquid) and smash it all away into little bits on the first hammer blow?

Emmett

As a kid, I thought it was to "smear the marines."