Lindy, I forgot to tell you, that I have taken the course already in August and since then I practised it with all three. I wanted to take the course again, because Slippie is much more difficultto train than the other two. Needs a lot of patience and I willl have to put up with it, that some exercises, she will never do.
When I wrote "go and try" it, I did not mean to do this now immediately. Only when you see, your dog got it and you have worked enough on duration. Sorry if I created a misunderstandig.
It is all -as Mark says - a question of many reps.
Keep on! Your lovely dog will learn it.
Christina