I know what yopu mean by the physical side. Perhaps I didn;t make it clear that you don;t force them into any position but merley suggestively guide them into position. For example.

I taught dog1 to sit be moving the treat over his head etc. I then lost the treat and if he didn;t respond after the first command a very light tap with my index finger on his curly haired bottom was enough to get him to follow the required action.

The physical suggestion is extremely hard to do for other commands such as lying down and should not be used as it would involve far too much manipulation to get your message across and the heavy handed approach would mean you lose all control and faith as far as the dog is concered which is why I emphasised watching your dog's behaviour and commanding when they naturally perform the action becasue then you are not using treats and you are not using physical persuasion.

Treats will only help you survive until a certain point and pysical pursasion will only work in limited situations and for a very short time so they must both be used with caution. One more so than the other.