This is exactly the best way to implement such a drastic change as you are in the process of doing. The problem with using your new stance, grip and stroke to pocket balls is when you keep missing you eventually revert back to what you did previously or get into some bad habits such as not cueing straight but instead cueing in a side was sweeping motion. If the reason is purely because you haven't mastered aligning correctly in your new fundamentals, then that's fine, as long as you are cueing straight.
By hitting hundreds, even thousands of balls into a pocket, by this I mean directly into a pocket like hitting the CB from the foot spot into a corner pocket at the other end of the table, you don't pick up nearly as many bad habits. You just concentrate on cueing in a straight line. Once you have your new fundamentals set in stone you can start implementing potting balls. This really does suck, but all the great snooker players I know of have had to do it when starting out.