I'd still be concerned that there would be places of dry cement that you can't see, sandwiched between the wet/cured concrete. Have you ever used this method, Jolly?
I wonder if that particular mix is made for this type of process, as opposed to the usual method.
Never done it, although I've heard it works. If I was going to try it, I'd do a very small project and use the 40 or 60 pound bags.
The mix he's using is just everyday Sakrete.
I’ve used the pour it dry stuff to mount tether ball poles, etc. but I’d not use if for anything structural like a patio.