Hi Niki
Yes these are great when you need lots of small clams quickly. Can I make a suggestion? When you embed a nut, drill the larger hole first (the one which will hold the nut) and only then drill right through for the rod, you get a cleaner and more accurate hole that way. If you do it as you suggest, you have nothing in which to locate the point of the bigger drill and the risk of snatching and wandering is increased.
Cheers
Steve