Yes, thats a great grip to keep your opponent hunched, not just for throws but also its wears them down very well if you drag them around the mat like that, and can run the time down if you need to. If you are right handed, keep the same left collar grip and put your right over
the back and ever try and grab the belt. From here, they have very little they can do other than try and catch one of your legs and do a pick up if you go half assed into an ashi waza. From here, osoto, uchimata, ouchi, sumi gaeshi, yoko tomoenage are all very easy to hit and as your opponent can see much, they are very vulnerable. Its why a lot of guys will fight tooth and nail to stop you getting it.