Timing is important here as we learned tonight. As Uke successfully grabs your first shoulder, shikko sideways (away from Uke) with timing such that it gives Uke more rotational momentum which he can’t fully control himself. As he reaches for the other shoulder, place your farthest knee out forward and press forward, bend your waist forward and use your body to generate a short, blending thrust to send Uke falling back where he came from.

If the second shoulder is not completely grabbed, a kind of tenbin can be done on his missed arm to finish the waza the same way.

Shifting sideways is not always needed. If you can use your koshi and rotate your torso then your shoulders will also rotate and can you can execute a similar waza this way.