My son also loses interest before the words are recycled. I got around it by just jumping around a bit. We watch one week for a few days then skip a few weeks and watch it for a few days and then go back to the original week. If you use IAccess it is really super easy to do, my son does it without my help now. We never do the same lesson twice in one day. I find by jumping around like this he is happy to watch lessons ( and see the same words) MORE times than the course shows them
We also do the LR curriculum on the iPad but use the computer for downloaded files to match his current interests ( or my interests I am imposing on him
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) this way he sees new words all the time, almost daily. Some from the lesson and some from the share files. Also kids will watch for longer if they think there is something in there especially for them. Add in his favourite toys, his own name, your pets, grandparents....just randomly will do to create a surprise element.
If you do decide to skip around I would recommend adding in some phonics practice to your day also. Reading bear.org would be perfect. I say this purely because as our kids like to see fresh wor so much they are not getting the repetition that other children get. This repetition, logically, could be the way children develop their reading brains and figure out the phonics code. Of course this is all speculation! But to be sure provide the phonics as a bonus extra or make sure the pattern phonics in LR is done in order each day. The pattern phonics in LR follows a logical sequence.