I'll test this out, sounds like a good strategy. I have also done something slightly different which is giving him a word without telling him the meaning, just playing with the sound. After a while once he can repeat it and say it fluently, I would explain what it means. By the time I do that, he's already said the word a bunch of times so I tricked him into "knowing" the word and there's nothing he can do to go back in time :)
