This counter works if you act fast, and it counters a rear choke or bear hug type restraint, swing your arm around, over their head, as you twist your body, get them in a headlock (around the painful part of the head above the eyes, on the temples, and you can take initiative as they are tackled.
The throw from Sochin is good, (attacking the hyperglossal and throwing them onto your knee http://www.fightingarts.com/reading/article.php?id=204
) and so is the elbow from Seiunchin http://www.fightingarts.com/reading/article.php?id=205
, but if you are grapping, the position ("positional dominance"?) of the opponent reflects as to how effective your counters will be.