Swap

Whenever the Sledgehammer algorithm is executed, it involves swapping corners located within the 'workbench'.

This means that after two repetitions, the cubies are in their original positions, but with a different orientation. Therefore:

Two consecutive 'Sledgehammer' rotate the 'corners'.

This has the important consequence that if a cubie is not correctly oriented, simply repeating the 'Sledgehammer' will eventually orient the cubie correctly.

U F' U' F F' U F U' R U' R' U U' R U R' F R' F' R R' F R F'

(Each of the six possible Sledgehammer alternatives swaps different cubies, always within the same 'workbench' and the same pattern.)