Go for it! I think you will be ok with dual duty. It may try snagging or knotting up a bit more due to the lighter weight and most likely not being coated in any way. You can easily solve that minor issue by using shorter lengths and/or coating with bees wax or one of the other products on the market. It shouldn't affect the strength of the quilt. Just give the dual duty a good firm tug, if it doesn't break easily I say use it. I am pretty sure I have used C&C dual duty for hand quilting, I know I have a couple of spools of it in my stash.