To help illustrate how the process works the following shows other ways of doing the same operation as 3C-E3. All of these sequences work the same way by flipping one of the two cubies (via quarter-twist of center slice on second move) then switching them (via half-twist on the fourth move), the last three moves are the inverse of the first three.

The first cube below shows a minor variation of the original sequence, it moves the two cubies to the top face (instead of the bottom) to switch them. The second cube shows another way to move the cubies to the top face to switch them. The third & fourth cubes are variations of the second cube that switch the cubies on the front and bottom faces.

The following shows other ways of doing the same operation as Sequence 3C-E4. The first cube has a different starting position. It shows a variation of the original sequence that moves the two cubies to the top face (instead of the bottom) to switch them. The second cube has the original starting position and shows another way to move the cubies to the top face to switch them. The third cube is a minor variation of the second which moves the cubies to the front face to switch them. The last cube is a minor variation of the original sequence that moves the two cubies to the front face to switch them.